Montrealers are being advised to prepare for a prolonged stretch of dangerous heat as a heat warning takes effect from Wednesday through Saturday, bringing sweltering temperatures and oppressive humidity across the city.
Monday offers a taste of what’s ahead, with mainly sunny skies, a high of 30 Celusis, and a humidex of 33. Tuesday will be slightly cooler at 28 C, with increasing cloud cover and a chance of afternoon showers before the more intense heat arrives.
Environment Climate Change Canada (ECCC) officials say daytime temperatures are expected to reach 30 to 33 C, while overnight lows will remain near 20 C, offering little opportunity for homes and buildings to cool down. Combined with high humidity, humidex values are forecast to climb between 40 C and 44 C, creating conditions that can quickly become hazardous.
Health officials warn that the prolonged heat could lead to heat exhaustion or heat stroke, particularly among seniors, young children, people with chronic medical conditions, outdoor workers, and those without access to air conditioning. The extreme humidity is also expected to increase discomfort for the general population.
The heat will build through the middle of the week. Wednesday is forecast to be mostly cloudy with a 30 per cent chance of showers and a high of 31 C. Thursday is expected to be the hottest day, with temperatures reaching 33 C under a mix of sun and cloud and a chance of showers. Sunny skies are forecast to return Friday with a high of 31 C, while Saturday will remain hot with a high near 30 C.
Officials are encouraging Montreal residents to drink plenty of water, avoid strenuous outdoor activity during the hottest part of the day, seek air-conditioned spaces whenever possible, and check in on neighbours, relatives, and friends who may be more vulnerable to extreme heat.
Although scattered showers are possible at times during the week, they are not expected to significantly reduce the heat or humidity. Relief is expected to be limit.
