forecast
detailed forecast
| Extented weather forecast for Cornwall Ontario and the Seaway Issued by Environment Canada at 1530 ET Sat Sep 12 2026 |
| Tonight: Clear. Increasing cloudiness this evening then 60 percent chance of showers overnight. Risk of a thunderstorm overnight. Wind southwest 20 km/h gusting to 40 becoming light early this evening. Low 19. Sunday: Mainly cloudy with 60 percent chance of showers and risk of a thunderstorm. Wind becoming west 30 km/h gusting to 50 in the morning. High 25. Humidex 33. Uv index 4 or moderate. Sunday Night: Increasing cloudiness early in the evening. Wind west 20 km/h gusting to 40 becoming light in the evening. Wind becoming northwest 20 gusting to 40 near midnight. Low 10. Monday: Sunny. High 18. Monday Night: Clear. Low plus 5. Tuesday: A mix of sun and cloud. High 21. Tuesday Night: Cloudy with 60 percent chance of showers. Low 15. Wednesday: Clearing. High 24. Wednesday Night: Increasing cloudiness. Low 13. Thursday: Cloudy with 60 percent chance of showers. High 21. Thursday Night: Cloudy. Low 11. Friday: A mix of sun and cloud. High 20. |
regional radar

■ Cornwall
Rain Snow Ice Mix













