Today – July 16, 2025
Mainly cloudy with 40 percent chance of showers. Risk of a thunderstorm. Wind becoming southwest 20 km/h late this morning. High 30. Humidex 40. UV index 7 or high.
Special air quality statement
Elevated levels of pollution due to ground level ozone is expected again today.
Air Quality Health Index (AQHI) values are expected to reach moderate to high risk this afternoon and evening as elevated levels of ozone are expected.
When air pollution levels are high, everyone should 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.
When indoors, keep windows and doors closed as much as possible. When there is an extreme heat event occurring with poor air quality, prioritize keeping cool.
Protect your indoor air from outdoor air pollution. Actions can include using a clean, good quality air filter in your ventilation system and/or a certified portable air cleaner.
Check in on others who are in your care or live nearby who may be more likely to be impacted by outdoor air pollution.
Always follow guidance from local authorities.
Visit 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.
Issued by Environment Canada and the Province of Ontario
Heat warning
Humidex values reaching 35 are expected for more than 5 days.
A prolonged period of hot and humidity continues.
What:
Daytime highs of 31 to 34 degrees Celsius and a humidex of 37 to 42.
Overnight lows of 19 to 21 degrees Celsius, providing little relief from the heat.
When:
Continuing through Thursday.
Additional information:
A cooler airmass is expected to arrive on Thursday night bringing an end to this heat event.
Take action to protect yourself and others – extreme heat can affect everyone’s health. Determine if you or others around you are at greater risk of heat illness. Check on older adults, those living alone and other at-risk people in-person or on the phone multiple times a day.
Watch for the early signs of heat exhaustion in yourself and others. Signs may include headache, nausea, dizziness, thirst, dark urine and intense fatigue. Stop your activity and drink water.
Heat stroke is a medical emergency! Call 9-1-1 or your emergency health provider if you, or someone around you, is showing signs of heat stroke which can include red and hot skin, dizziness, nausea, confusion and change in consciousness. While you wait for medical attention, try to cool the person by moving them to a cool place, removing extra clothing, applying cold water or ice packs around the body.
Drink water often and before you feel thirsty to replace fluids.
Close blinds, or shades and open windows if outside is cooler than inside.
Turn on air conditioning, use a fan, or move to a cooler area of your living space. If your living space is hot, move to a cool public space such as a cooling centre, community centre, library or shaded park.
Follow the advice of your region’s public health authority.
Plan and schedule outdoor activities during the coolest parts of the day.
Limit direct exposure to the sun and heat. Wear lightweight, light-coloured, loose-fitting clothing and a wide-brimmed hat.
Never leave people, especially children, or pets inside a parked vehicle. Check the vehicle before locking to make sure no one is left behind.
For more information: How to protect yourself from the health effects of extreme heat Health risks and who is at risk of extreme heat events
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.
Tonight
Mainly cloudy. 40 percent chance of showers early this evening and before morning. Risk of a thunderstorm. Wind becoming southwest 20 km/h after midnight. Low 24.
Thu, 17 Jul – Mainly cloudy with 60 percent chance of showers and risk of a thunderstorm. Wind west 30 km/h. High 27. Humidex 35. UV index 7 or high. Night – Cloudy periods with 40 percent chance of showers. Low 14.
Fri, 18 Jul – A mix of sun and cloud with 30 percent chance of showers. High 24. Night – Cloudy periods. Low 17.
Sat, 19 Jul – Cloudy. High 26. Night – Cloudy with 40 percent chance of showers. Low 19.
Sun, 20 Jul – A mix of sun and cloud with 60 percent chance of showers. High 27. Night – Cloudy periods with 30 percent chance of showers. Low 17.
Mon, 21 Jul – A mix of sun and cloud. High 28. Night – Cloudy periods. Low 20.
Tue, 22 Jul – A mix of sun and cloud. High 31.
