Extreme heat warning in effect for Ottawa on Canada Day

A hot, humid day at Kiweki Point in Ottawa. June 11, 2026. (CTV News Ottawa)

Environment Canada is warning of extreme heat in the Ottawa area on Canada Day and continuing through the weekend.

According to Environment Canada’s orange warning – heat, the temperature will reach a high of 35 C on Wednesday, and the humidex may reach 46. The overnight low is only expected to be 23 C.

“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,” Environment Canada said.

The orange level on Environment Canada’s colour-coded scale refers to weather that is likely to cause significant damage, disruption or health impacts. Environment Canada is advising residents to take steps to protect themselves from the heat.

“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,” Environment Canada wrote.

“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.”

If someone is displaying signs of heat stroke, including red and hot skin, dizziness, nausea, confusion and loss of consciousness, 911 should be contacted immediately.

“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,” Environment Canada wrote.

• How to deal with heat exhaustion and heat stroke

Environment Canada recommends taking the following steps to deal with the heat:

• Limit exposure to the sun and heat
• Wear lightweight and light-coloured clothes
• Close blinds and shades, and open windows if it is cooler outside than inside
• Turn on air conditioning and use fans
• Move to cooler areas of your living space
• If there are no cool areas in your living space, move to a cool public place like a pool, cooling centre, community centre or library
• Drink water before you feel thirsty to replace fluids

The organization says air quality may be poor due to the heat and humidity, and the UV index is expected to reach 9 or higher.

In addition to the heat, there is a 40 per cent chance of showers and a risk of a thunderstorm in the afternoon on Wednesday.

Forecast

The heat warning is expected to continue through the weekend, with Wednesday and Thursday being the hottest days.

Thursday’s forecast predicts another day of 34 C, with a 40 per cent chance of showers.

On Friday, expect 33 C and a chance of showers.

On Saturday, expect 31 C and a chance of showers.

On Sunday, temperatures are expected to dip below 30 C, reaching a high of only 29 C.

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