Ajax is in the grip of a dangerous heat wave that will get worse before it gets better. Environment Canada has issued a heat warning for the area, with the hottest day expected Tuesday, July 14, 2026.
Temperatures are forecast to hit 36 degrees Celsius, well above the normal high of 26 for this time of year. With humidity factored in, it will feel closer to 43. The UV index is expected to reach 9, which is considered very high.
Monday saw the mercury climb to 32 degrees with a humidex of 37 at the Oshawa Executive Airport weather station. The heat is not expected to break until Wednesday or Thursday evening.
The warning covers the entire Pickering, Oshawa, and southern Durham Region. It is the second major heat event to hit southern Ontario in less than two weeks. Toronto hospitals recorded 39 heat-related emergency room visits during the previous stretch from June 30 to July 4.
Hot, humid air can also worsen air quality. The Air Quality Health Index may approach the high-risk category over the coming days. Residents in urban heat islands like parts of Ajax may feel the heat more intensely, according to a 2024 Durham Region health report.
Officials stress that heat stroke is a medical emergency. Warning signs include hot, red skin, dizziness, nausea, confusion, or a change in consciousness. Anyone showing these symptoms should call 911 right away.
People are urged to drink plenty of water, stay out of the sun during the hottest part of the day, and wear light-coloured, loose clothing. Check on older neighbours, those who live alone, and others who may be at risk. If your home gets too hot, head to a cooling centre, library, or shaded park.
