A prolonged heat wave is set to grip Grimsby this week, with Environment Canada issuing an orange heat warning for the town and surrounding Niagara Region on Monday afternoon. Temperatures are forecast to climb as high as 34 degrees Celsius, with humidity making it feel closer to 42, and the sweltering conditions are expected to last from Tuesday through at least Friday.
The Environment Canada warning notes that Wednesday and Thursday will be the hottest days, with daytime highs potentially reaching 37 C in some areas. Overnight lows of 21 to 25 C will offer little relief, and the UV index is expected to hit 9, or very high, on Tuesday. The heat and humidity may also cause air quality to deteriorate, pushing the Air Quality Health Index toward the high-risk category.
This is roughly 6 to 12 degrees above the seasonal norm of 25 C for late June and early July. The warning meets Ontario’s Harmonized Heat Warning and Information System criteria, which triggers an alert when daytime highs reach at least 31 C and overnight lows stay at or above 20 C, or when humidex values hit 40, for two or more days.
Officials are urging residents to check on neighbours, especially seniors living alone, infants, people with chronic illnesses, and those without air conditioning. Niagara Region reminds everyone that heat stroke is a medical emergency; signs include confusion, dizziness, nausea, and hot, red skin. Anyone seeing these symptoms should call 911. Cooling centres at local libraries, community centres, and recreation facilities are open for those needing a break from the heat.
The risk is real: a Statistics Canada study found about 670 excess deaths occurred during extreme heat events in major Canadian cities between 2000 and 2020. Grimsby residents are advised to drink plenty of water, stay in air-conditioned spaces when possible, and limit outdoor activity during the peak afternoon hours.
