Sarnia Weather Forecast

Rain, heavy at times is expected. The ground, already near saturation, has little ability to absorb further rainfall. What: Rain, at times heavy. Total rainfall amounts of 30 to 50 mm. Locally higher amounts near 75 mm are possible if thunderstorms repeatedly impact the same area. When: Through early Thursday morning. Additional information: With thunderstorms expected, rainfall amounts may exceed 50 mm over some areas, particularly over southwestern Ontario. Rain will end from west to east overnight into early Thursday morning. For information concerning flooding, please consult your local Conservation Authority or Ontario Ministry of Natural Resources office. Visit Ontario.ca/floods for the latest details. ### Localized flooding in low-lying areas is possible. Heavy downpours can cause flash floods and water pooling on roads. Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm.

Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts. What: Wind gusts to 90 km/h and nickel size hail. When: Beginning this evening and ending after midnight. Additional information: A line of thunderstorms over Lower Michigan will track east into southwestern Ontario this evening. ### Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles. Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could produce one or more of the following: large hail, damaging winds, torrential rainfall. Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@ec.gc.ca or post reports on X using #ONStorm. For more information: https://www.ontario.ca/page/be-prepared-emergency.