frost
Frost may damage some crops in frost-prone areas.
Temperatures are expected to fall to near the freezing mark again tonight.
###
Damage to plants, trees, and crops is possible.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 28, 2025 16:19
Until: Oct 29, 2025 12:51
frost
Frost may damage some crops in frost-prone areas.
Temperatures are expected to fall to near the freezing mark again tonight.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 28, 2025 13:11
Until: Oct 29, 2025 05:11
frost
Frost may damage some crops in frost-prone areas.
Temperatures are expected to fall to near the freezing mark again tonight into early Tuesday morning.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 27, 2025 16:14
Until: Oct 28, 2025 08:14
frost
Frost may damage some crops in frost-prone areas.
Temperatures are expected to fall to the freezing mark overnight into early Monday morning.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 26, 2025 14:34
Until: Oct 27, 2025 16:00
frost
Frost may damage some crops in frost-prone areas.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 26, 2025 19:28
Until: Oct 27, 2025 11:28
frost
Frost may damage some crops in frost-prone areas.
Temperatures are expected to fall to the freezing mark overnight into early Sunday morning.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Oct 25, 2025 19:41
Until: Oct 26, 2025 11:41
Beach Hazards Statement
* WHAT...Strong currents and dangerous swimming conditions.
* WHERE...Beaches of Niagara, Orleans, and Northern Cayuga
counties.
* WHEN...Through late Wednesday night.
* IMPACTS...Strong currents and dangerous swimming conditions.
From: Sep 30, 2025 19:56
Until: Oct 02, 2025 09:00
squall
Conditions are favourable for the development of squalls with wind gusts up to 35 knots and frequent lightning.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
From: Sep 23, 2025 19:25
Until: Sep 24, 2025 04:59
fog
Near zero visibility in fog is expected or occurring over some areas.
Fog will dissipate late this morning.
###
Visibility may be significantly and suddenly reduced to near zero.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Sep 10, 2025 13:05
Until: Sep 10, 2025 16:59
fog
Near zero visibility in fog is expected or occurring over some areas.
###
Visibility may be significantly and suddenly reduced to near zero.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Sep 10, 2025 13:05
Until: Sep 10, 2025 16:59
fog
Visibilities have improved and are no longer expected to meet fog advisory criteria.
###
From: May 06, 2025 11:51
Until: Sep 10, 2025 15:03
fog
Near zero visibility in fog is expected or occurring.
Fog is expected to dissipate this morning.
###
Visibility may be significantly and suddenly reduced to near zero.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Sep 10, 2025 08:46
Until: Sep 10, 2025 15:01
squall
Squalls with wind gusts up to 35 knots, frequent lightning and poor to very poor visibility in showers heavy at times are expected or occurring in the area.
###
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
From: Sep 04, 2025 11:44
Until: Sep 04, 2025 14:29
Beach Hazards Statement
* WHAT...Strong currents and dangerous swimming conditions.
* WHERE...Beaches of Niagara and Orleans counties.
* WHEN...Through this evening.
* IMPACTS...Strong currents and dangerous swimming conditions.
From: Aug 26, 2025 08:32
Until: Aug 27, 2025 03:00
waterspout
Conditions are favourable for the development of waterspouts over the Great Lakes today. The potential for waterspouts may continue tonight into Wednesday over Lake Erie and Lake Ontario.
###
Wind speeds inside the spray ring of a waterspout are 45 knots or higher. Vulnerable vessels are at risk of damage or capsizing.
Waterspouts are generally isolated in nature although they can also occur in families of two or more. Spray rings associated with waterspouts can measure in the tens of metres. Waterspouts sometimes appear as funnel clouds with swirling water visible near the surface.
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
From: Aug 26, 2025 07:05
Until: Aug 26, 2025 23:05
Beach Hazards Statement
* WHAT...Strong currents and dangerous swimming conditions
expected.
* WHERE...Beaches of Niagara and Orleans counties.
* WHEN...From 11 AM EDT this morning through Tuesday evening.
* IMPACTS...Strong currents and dangerous swimming conditions.
From: Aug 25, 2025 07:59
Until: Aug 25, 2025 16:00
thunderstorm
Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and large hail.
Hazards:
Wind gusts up to 90 kilometres per hour.
Up to toonie sized hail.
When:
This evening.
###
Local utility outages are possible. Damage to roofs, fences, branches or soft shelters is possible.
Severe thunderstorm watches are issued when conditions are favourable for the development of thunderstorms capable of producing damaging hail, wind or rain.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
For more information: https://www.ontario.ca/page/be-prepared-emergency.
From: Aug 23, 2025 21:14
Until: Aug 24, 2025 05:01
thunderstorm
Conditions are no longer favourable for the development of severe thunderstorms.
###
From: Aug 24, 2025 02:20
Until: Aug 24, 2025 03:20
Beach Hazards Statement
* WHAT...Strong currents and dangerous swimming conditions.
* WHERE...Beaches of Niagara and Orleans counties.
* WHEN...Until 4 PM EDT this afternoon.
* IMPACTS...Strong currents and dangerous swimming conditions.
From: Aug 18, 2025 10:10
Until: Aug 18, 2025 20:00
heat
Multi-day heat event continues.
What:
Daytime highs near 31 degrees Celsius, with humidex values up to 40.
When:
Coming to an end later today.
Additional information:
A cooler and less humid air mass will slowly move in from the northwest today, bringing the heat event to an end.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 13, 2025 13:34
Until: Aug 14, 2025 05:34
heat
Multi-day heat event continues.
What:
Daytime highs of 30 to 33 degrees Celsius, with humidex values of 37 to 40.
When:
Coming to an end later today.
Additional information:
A cooler and less humid air mass will slowly move in from the northwest today, bringing the heat event to an end.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 13, 2025 13:01
Until: Aug 14, 2025 05:01
heat
Multi-day heat event continues.
What:
Daytime highs of 30 to 32 degrees Celsius, with humidex values of 37 to 40.
Overnight lows near 20 degrees Celsius.
When:
Continuing through Tuesday.
Additional information:
A cooler air mass is expected to arrive Tuesday night, bringing an end to this heat event.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 11, 2025 22:14
Until: Aug 12, 2025 14:14
heat
Multi-day heat event continues.
What:
Daytime highs of 32 to 35 degrees Celsius, with humidex values of 37 to 42.
Overnight lows of 20 to 23 degrees Celsius.
When:
Continuing through Tuesday or possibly Wednesday for some areas.
Additional information:
A cooler air mass is expected to arrive Tuesday night, bringing an end to this heat event. There is the possibility that eastern Ontario and the Greater Toronto and Hamilton Area could see hot and humid conditions continue into Wednesday.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 11, 2025 22:07
Until: Aug 12, 2025 14:09
heat
Multi-day heat event continues.
What:
Daytime highs of 32 to 35 degrees Celsius, with humidex values of 37 to 40.
Overnight lows of 20 to 23 degrees Celsius.
When:
Continuing through Tuesday or possibly Wednesday for some areas.
Additional information:
A cooler air mass is expected to arrive Tuesday night, bringing an end to this heat event. There is a possibility that eastern Ontario and the Greater Toronto and Hamilton Area see hot and humid conditions into Wednesday.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 10, 2025 19:39
Until: Aug 11, 2025 11:39
heat
Multi-day heat event continues.
What:
Daytime highs of 30 to 35 degrees Celsius, with humidex values of 35 to 40.
Overnight lows of 19 to 22 degrees Celsius.
When:
Continuing through Tuesday or possibly Wednesday for some areas.
Additional information:
Slightly cooler temperatures are expected by Wednesday, bringing an end to this heat event.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 10, 2025 11:09
Until: Aug 11, 2025 03:09
heat
Multi-day heat event expected.
What:
Daytime highs of 30 to 35 degrees Celsius, with humidex values of 35 to 40.
Overnight lows of 19 to 22 degrees Celsius.
When:
Continuing through Tuesday or possibly Wednesday for some areas.
Additional information:
Slightly cooler temperatures are expected by Wednesday, bringing an end to this heat event.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Aug 10, 2025 05:10
Until: Aug 10, 2025 21:10
air quality
Smoke is causing or expected to cause poor air quality and reduced visibility.
Smoke from forest fires is expected to continue to affect much of southern Ontario tonight. The wildfire smoke may persist into Tuesday and possibly Wednesday.
Air quality and visibility due to wildfire smoke can fluctuate over short distances and can vary considerably from hour to hour.
###
As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events.
You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.
People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms.
Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values.
Please continue to monitor alerts and forecasts issued by Environment Canada.
From: Aug 04, 2025 19:25
Until: Aug 05, 2025 18:45
Air Quality Alert
The New York State Department of Environmental Conservation at
Albany has issued an Air Quality Health Advisory for Fine
Particulates until midnight EDT Monday night.
Air quality levels in outdoor air are predicted to be greater than
an Air Quality Index value of 100 for Fine Particulates. The Air
Quality Index...or AQI...was created as an easy way to correlate
levels of different pollutants to one scale. The higher the AQI
value...the greater the health concern.
When pollution levels are elevated...the New York State Department
of Health recommends that individuals consider limiting strenuous
outdoor physical activity to reduce the risk of adverse health
effects. People who may be especially sensitive to the effects of
elevated levels of pollutants include the very young and those with
pre-existing respiratory problems such as asthma or heart disease.
Those with symptoms should consider consulting their personal
physician.
For additional information, please visit the New York State
Department of Environmental Conservation website at,
https://on.ny.gov/nyaqi, or call the Air Quality Hotline at
1 800 5 3 5, 1 3 4 5.
From: Aug 03, 2025 21:52
Until: Aug 05, 2025 04:00
air quality
Smoke is causing or expected to cause poor air quality and reduced visibility.
###
As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events.
You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.
People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms.
Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values.
Please continue to monitor alerts and forecasts issued by Environment Canada.
From: Jun 05, 2025 19:36
Until: Aug 05, 2025 01:29
air quality
Smoke is causing or expected to cause poor air quality and reduced visibility.
Smoke from forest fires is expected to continue to affect much of southern Ontario today. The wildfire smoke may persist into tonight and possibly Tuesday before finally easing.
Air quality and visibility due to wildfire smoke can fluctuate over short distances and can vary considerably from hour to hour.
###
As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events.
You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.
People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms.
Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values.
Please continue to monitor alerts and forecasts issued by Environment Canada.
From: Aug 04, 2025 09:29
Until: Aug 05, 2025 01:29
air quality
Smoke is causing or expected to cause poor air quality and reduced visibility.
Smoke from forest fires is expected to continue to affect much of southern Ontario tonight. The wildfire smoke may persist into Monday for parts of southern Ontario.
Air quality and visibility due to wildfire smoke can fluctuate over short distances and can vary considerably from hour to hour.
###
As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events.
You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.
People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms.
Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values.
Please continue to monitor alerts and forecasts issued by Environment Canada.
From: Aug 04, 2025 00:58
Until: Aug 04, 2025 16:58
waterspout
Weather radar indicates that potential waterspout activity may be occurring in the area. Conditions are favourable for waterspout activity to continue.
A weak boundary has developed near the international border that may be producing waterspouts. This boundary is expected to move southward through the day as winds becoming more northerly.
###
Wind speeds inside the spray ring of a waterspout are 45 knots or higher. Vulnerable vessels are at risk of damage or capsizing.
Waterspouts are generally isolated in nature although they can also occur in families of two or more. Waterspouts are generally short-lived in nature, typically lasting 20 minutes or less. Spray rings associated with waterspouts can measure in the tens of metres.
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
From: Aug 01, 2025 13:35
Until: Aug 01, 2025 22:59
waterspout
Weather radar indicates that potential waterspout activity may be occurring in the area. Conditions are favourable for waterspout activity to continue.
###
Wind speeds inside the spray ring of a waterspout are 45 knots or higher. Vulnerable vessels are at risk of damage or capsizing.
Waterspouts are generally isolated in nature although they can also occur in families of two or more. Waterspouts are generally short-lived in nature, typically lasting 20 minutes or less. Spray rings associated with waterspouts can measure in the tens of metres.
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
From: Aug 01, 2025 13:35
Until: Aug 01, 2025 22:59
air quality
Smoke is causing or expected to cause poor air quality and reduced visibility.
Smoke from forest fires over the Prairies has moved over the area causing poor air quality.
Air quality is expected to improve from north to south on Thursday.
###
As smoke levels increase, health risks increase. Limit time outdoors. Consider reducing or rescheduling outdoor sports, activities and events.
You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough. More serious but less common symptoms include wheezing, chest pains or severe cough. If you think you are having a medical emergency, seek immediate medical assistance.
People more likely to be impacted by outdoor air pollution, including people aged 65 and older, pregnant people, infants and young children, people with an existing illness or chronic health condition, and people who work outdoors, should reduce or reschedule strenuous activities outdoors and seek medical attention if experiencing symptoms.
Visit http://www.airhealth.ca for information on how to reduce your health risk and your personal contribution to pollution levels, as well as for current and forecast AQHI values.
Please continue to monitor alerts and forecasts issued by Environment Canada.
From: Jul 30, 2025 22:56
Until: Jul 31, 2025 14:56
heat
A multi-day period of heat and humidity continues.
Tuesday:
Nighttime lows near 20 degrees Celsius.
Wednesday:
Daytime temperatures near 31 degrees Celsius.
Peak humidex values near 36.
When:
Ending Wednesday evening.
Additional information:
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category.
###
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 30, 2025 03:01
Until: Jul 30, 2025 19:02
heat
A multi-day period of heat and humidity continues.
What:
Daytime high temperatures of 30 to 33 degrees Celsius.
Humidex values of 38 to 43.
Nighttime low temperatures of 20 to 23 degrees Celsius, providing little relief from the heat.
When:
Continuing through Tuesday. Ending Tuesday night.
Additional information:
Confidence has increased that cooler temperatures will arrive on Wednesday, bringing an end to the heat event.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 29, 2025 04:17
Until: Jul 29, 2025 20:17
heat
A multi-day period of heat and humidity continues.
What:
Daytime high temperatures of 30 to 33 degrees Celsius.
Humidex values of 38 to 43.
Nighttime low temperatures of 19 to 21 degrees Celsius, providing little relief from the heat.
When:
Today through Tuesday. Ending Tuesday night.
Additional information:
The hottest conditions are expected today and Tuesday. Confidence has increased that cooler temperatures will arrive on Wednesday, bringing an end to the heat event.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 28, 2025 09:27
Until: Jul 29, 2025 01:27
heat
A multi-day period of heat and humidity continues.
What:
Daytime high temperatures of 30 to 34 degrees Celsius.
Humidex values of 38 to 42.
Nighttime low temperatures of 19 to 23 degrees Celsius, providing little relief from the heat.
When:
Today through Tuesday. Possibly continuing into Wednesday.
Additional information:
The hottest conditions are expected on Monday and Tuesday. There is some uncertainty in the duration of the heat event, with some areas possibly continuing into Wednesday.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 27, 2025 20:04
Until: Jul 28, 2025 12:04
heat
A multi-day heat event begins today.
What:
Daytime high temperatures of 30 to 34 degrees Celsius.
Humidex values of 38 to 42.
Nighttime low temperatures of 19 to 23 degrees Celsius, providing little relief from the heat.
When:
Today through Tuesday.
Additional information:
The hottest conditions are expected on Monday. There is some uncertainty in the duration of the heat event for some regions. In central Ontario, the heat event may end Monday night. Over some areas the heat event could persist into Wednesday.
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 27, 2025 08:48
Until: Jul 28, 2025 00:48
heat
###
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 27, 2025 08:48
Until: Jul 28, 2025 00:48
heat
###
From: Jul 27, 2025 20:04
Until: Jul 27, 2025 20:04
heat
Heat event ending tonight.
What:
Daytime high temperatures near 30 degrees Celsius.
Peak humidex values near 40.
Nighttime low temperatures near 21 degrees Celsius, providing little relief from the heat.
When:
Ending tonight.
Additional information:
A relatively cooler day is expected Saturday before hotter temperatures likely return on Sunday.
###
For more information: https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/how-protect-yourself.html https://www.canada.ca/en/health-canada/services/climate-change-health/extreme-heat/who-is-at-risk.html
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.
From: Jul 26, 2025 02:27
Until: Jul 26, 2025 08:59
