Environment Canada's forecast of severe thunderstorms ended just before 6:30 p.m. on Wednesday.
A severe thunderstorm watch was issued for Sarnia-Lambton, western Middlesex County, western Elgin County, Chatham-Kent, and Windsor-Essex over the noon hour.
A severe thunderstorm warning was issued for Windsor-Essex, which ended at around 4:20 p.m.
A warning was also put into effect for Sarnia, Petrolia and Western Lambton County just before 4 p.m. It was lifted at around 5:20 p.m.
The weather agency described the main threats as strong wind gusts up to 90 km/h, hail up to 2.5 cm in diameter or quarter size, and the risk of an isolated, brief tornado.
Environment Canada said large hail can damage property and cause injury.
Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles. Locally heavy rain is also possible. Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches.