forecast
detailed forecast
| Extented weather forecast for Cornwall Ontario and the Seaway Issued by Environment Canada at 1500 utc May 27 2026 |
| Today: Sunny. Becoming a mix of sun and cloud this afternoon. Wind northwest 20 km/h. High 24. Humidex 26. Uv index 8 or very high. Tonight: Cloudy. 30 percent chance of showers this evening. Wind north 20 km/h. Low 10. Thursday: Cloudy. 30 percent chance of showers late in the morning and in the afternoon. Wind northwest 30 km/h. High 21. Uv index 4 or moderate. Thursday Night: Cloudy periods. Low 10. Friday: Cloudy with 60 percent chance of showers. High 20. Friday Night: Cloudy with 60 percent chance of showers. Low 10. Saturday: A mix of sun and cloud with 30 percent chance of showers. High 19. Saturday Night: Clear. Low 9. Sunday: Cloudy with 40 percent chance of showers. High 19. Sunday Night: Cloudy periods with 40 percent chance of showers. Low 9. Monday: A mix of sun and cloud with 30 percent chance of showers. High 19. Monday Night: Cloudy periods. Low 10. Tuesday: A mix of sun and cloud. High 22. |














