Thunder Bay is experiencing a chilly start to Thursday, May 21, 2026, due to a frost warning in place for the city. The temperatures at Thunder Bay Airport recorded early this morning were below freezing, setting a cold backdrop for the day ahead.
Weather Conditions in Thunder Bay
- Temperature: -1.7°C
- Wind Chill: -4°C
- Wind: WNW at 5 km/h
- Humidity: 91%
- Visibility: 32 km
- Pressure: 103.1 kPa and rising
The forecast indicates that patchy frost could persist, particularly tonight into Friday morning. Consequently, sensitive plants and crops may be at risk of damage. Gardeners are advised to take precautions by covering plants and delaying the planting of tender annuals until the temperatures warm up.
Daytime Outlook
As the day progresses, sunny conditions will prevail. Southeast winds are expected to increase, reaching speeds of 20 km/h later in the morning. The anticipated high temperature is expected to be around 15°C, with a UV Index rating of 6, indicating high sun exposure risk.
Extended Forecast
Tonight’s forecast predicts clear skies with a low of -1°C and potential for patchy frost. The weather is set to improve as we head into the weekend:
- Friday: Sunny, high of 13°C.
- Saturday: Cloudy with a 60% chance of showers, high of 12°C.
- Sunday: Cloudy with a 40% chance of showers, high of 11°C.
A significant warm-up is expected next week, with temperatures climbing to around 24°C on Monday, followed by highs of 22°C on Tuesday and Wednesday.
