Residents in Sarnia, Ontario, can expect a dramatic shift in weather this weekend, as a cool Saturday gives way to a significantly warmer day on Sunday. According to Environment Canada, the temperature is set to climb to 23°C on Sunday, April 12, 2026, which is well above the seasonal average high of 12°C for this time of year.
Saturday began with chilly conditions, with the Sarnia Chris Hadfield Airport recording a temperature of 0.6°C at 5:00 AM. While Saturday is expected to see clearing skies and a high of 11°C, those looking forward to outdoor plans on Sunday should prepare for changing conditions.
Sunday’s forecast includes a 70 percent probability of morning showers. In addition to the warmth, residents should anticipate gusty south winds reaching up to 50 km/h. With a forecast Humidex of 25, the air may feel notably humid throughout the day.
This temperature spike is part of a wider trend across southwestern Ontario. The Weather Network reports that the region will see temperatures climb into the 20s, accompanied by periods of unsettled weather and the potential for thunderstorms through the middle of next week. Currently, there are no weather alerts in effect for the Sarnia area.
