Residents across Durham Region should prepare for another hot and humid day on Saturday, July 4, with temperatures expected to feel close to 40°C and a risk of showers and thunderstorms, according to Environment Canada.
The weather agency is forecasting a mix of heat, humidity, and unstable conditions across southern Ontario, including Oshawa, Whitby, Ajax, Pickering, Clarington, Brock, Scugog, and Uxbridge. Heat warnings remain in effect for much of the region as oppressive conditions continue into the weekend.
Saturday morning is expected to begin with cloudy skies and a 40 per cent chance of showers, along with the possibility of thunderstorms. Environment Canada says the unsettled weather could develop early in the day before temperatures climb through the afternoon.
Despite the cloud cover, daytime temperatures are forecast to reach around 30°C across Durham Region. However, with high humidity levels, it is expected to feel much hotter, with the humidex approaching 40°C in some areas.
A west wind of approximately 20 km/h is also expected, although it will provide only limited relief from the intense heat.
Environment Canada is advising residents to take precautions during the heat warning by staying hydrated, avoiding prolonged outdoor activity during the hottest part of the day, and seeking air-conditioned or shaded spaces whenever possible. Older adults, young children, people with chronic illnesses, and outdoor workers are considered most vulnerable to heat-related illnesses.
Health officials recommend drinking water regularly, even before feeling thirsty, wearing lightweight and light-coloured clothing, and checking on neighbours, family members, and others who may require assistance during extreme temperatures.
Saturday’s weather may also become hazardous as conditions become more unstable throughout the day. Environment Canada says there is a continued risk of thunderstorms, which could produce brief periods of heavy rainfall, gusty winds, and lightning.
The unsettled conditions are expected to continue into Saturday night, with cloudy skies, another 40 per cent chance of showers, and the ongoing possibility of thunderstorms across Durham Region and the Greater Toronto Area. Overnight temperatures are expected to remain warm, with lows near 19°C.
Looking ahead, Sunday is expected to bring some relief from the extreme heat. Environment Canada is forecasting cloudy skies, a 30 per cent chance of showers, and a daytime high of approximately 26°C, making for more comfortable conditions compared to Saturday.
The latest forecast follows several days of hot and humid weather that have affected communities across southern Ontario. Residents planning outdoor activities, sporting events, festivals, or travel throughout Durham Region are encouraged to monitor updated forecasts, particularly if thunderstorms develop.
Environment Canada notes that weather conditions can change quickly during periods of heat and atmospheric instability. Residents are encouraged to stay informed through official weather updates and be prepared to adjust outdoor plans if severe weather warnings are issued.





















