Heat warning
Environment Canada issued a Yellow Heat Warning for Chatham-Kent, Ontario at 4:06 a.m. EDT on Wednesday, September 2, 2026, warning of a moderate-impact heat event with high confidence in the forecast.
The agency said daytime highs will reach 30 to 32 degrees Celsius, with overnight lows of 20 to 23 degrees and humidex values near 40. The heat is expected to persist through Wednesday and could extend into Thursday in extreme southwestern Ontario, though Environment Canada said confidence in that extension is low. It added that Windsor and Essex County could also see the heat continue into Thursday, but confidence there is similarly low.
Officials urged residents to check on older adults, people living alone and others at greater risk of heat illness multiple times a day, in person or by phone. They said early signs of heat exhaustion include headache, nausea, dizziness, thirst, dark urine and fatigue, and advised anyone experiencing those symptoms to stop activity and drink water.
Heat stroke, which can cause red and hot skin, dizziness, nausea, confusion and altered consciousness, is a medical emergency, Environment Canada said, urging people to call 911 and attempt to cool the affected person with cold water, ice packs or by moving them somewhere cooler while awaiting help.
The agency recommended drinking water regularly before feeling thirsty, closing blinds, using air conditioning or fans, and seeking out cooling centres, libraries or shaded parks if home is too hot. It also advised scheduling outdoor activities for cooler parts of the day, wearing light, loose-fitting clothing, and never leaving people or pets inside parked vehicles.
Environment Canada asked the public to continue monitoring its alerts and forecasts, and to report severe weather by emailing ONstorm@ec.gc.ca or posting on social media with the hashtag #ONStorm.
Today – September 2, 2026
A mix of sun and cloud with 60 percent chance of showers. Risk of a thunderstorm. Wind becoming southwest 20 km/h gusting to 40 this afternoon. High 31. Humidex 42. UV index 7 or high.
Tonight
Cloudy. 40 percent chance of showers early this evening. Showers with thunderstorms beginning this evening. Risk of a thunderstorm early this evening. Local amount 15 to 25 mm. Low 21.
Thu, 3 Sep – Mainly cloudy. 40 percent chance of showers early in the morning. 60 percent chance of showers in the afternoon. Risk of a thunderstorm. High 29. Humidex 37. UV index 8 or very high. Night – Cloudy periods with 40 percent chance of showers. Low 20.
Fri, 4 Sep – A mix of sun and cloud with 30 percent chance of showers. High 28. Night – Cloudy periods. Low 18.
Sat, 5 Sep – A mix of sun and cloud. High 27. Night – Cloudy periods. Low 16.
Sun, 6 Sep – A mix of sun and cloud. High 26. Night – Cloudy periods. Low 17.
Mon, 7 Sep – A mix of sun and cloud with 30 percent chance of showers. High 27. Night – Cloudy periods. Low 16.
Tue, 8 Sep – A mix of sun and cloud. High 26.
