Whitby, Ontario is in for a stretch of hot and humid weather this week, with temperatures set to climb into the high 20s and feel even warmer due to the humidity. Environment Canada’s forecast shows Monday’s high of 26°C, with a Humidex of 28, is just the start of a warming trend that will peak Thursday at 30°C.
The stickiest day looks to be Tuesday, when the temperature is expected to reach 29°C and the Humidex could hit 35, making it feel more like the mid-30s. There is also a 40 percent chance of afternoon showers and a risk of a thunderstorm. Thursday will bring a mix of sun and cloud with a 40 percent chance of showers and a high of 30°C.
On both Monday and Tuesday, the UV index is forecast to be 9, which is considered very high. Environment Canada recommends avoiding direct sun between 11 a.m. and 3 p.m., applying SPF 30+ sunscreen generously and often, and wearing protective clothing.
Despite the uncomfortable conditions, no heat warning has been issued for Durham Region. The Durham Region Health Department confirms there is no alert in effect, as the criteria for a heat warning have not been met. A warning requires at least two consecutive days with daytime highs of 31°C or warmer and overnight lows of 20°C or higher, or Humidex values of 40 or above for two or more days. None of those thresholds are currently in the forecast.
Residents are still urged to take precautions during the hot spell, especially those at higher risk for heat-related illness. Adults 60 years or older, infants, young children, pregnant people, and those with chronic health conditions should be particularly careful. Staying hydrated, seeking air-conditioned spaces, and checking on neighbours living alone can help everyone stay safe. The Town of Whitby continues to implement its Climate Emergency Response Plan, which has been active since September 2023 to help the community cope with more frequent extreme weather.
