Extented weather forecast for Cornwall Ontario and the Seaway Issued by Environment Canada at 1930 utc Jul 11 2025

Tonight: Partly cloudy with 30 percent chance of showers early this evening then clear. Risk of a thunderstorm early this evening. Low 18. Saturday: Sunny. Increasing cloudiness late in the morning then 30 percent chance of showers late in the afternoon. Risk of a thunderstorm late in the afternoon. Wind becoming southeast 30 km/h late in the afternoon. High 32. Humidex 40. Uv index 9 or very high. Saturday Night: Partly cloudy. 30 percent chance of showers early in the evening. 40 percent chance of showers overnight. Risk of a thunderstorm early in the evening. Low 22. Sunday: Cloudy with 70 percent chance of showers. High 31. Sunday Night: Cloudy with 60 percent chance of showers. Low 19. Monday: Sunny. High 29. Monday Night: Clear. Low 19. Tuesday: Sunny. High 30. Tuesday Night: Cloudy periods. Low 19. Wednesday: Cloudy. High 29. Wednesday Night: Cloudy with 40 percent chance of showers. Low 20. Thursday: Cloudy with 40 percent chance of showers. High 25.