THUNDER BAY – WEATHER DESK – Thunder Bay is starting Thursday waking up to another chilly May morning with mostly cloudy skies, temperatures hovering just above freezing, and the lingering possibility of flurries.
While spring warmth is slowly building, Northwestern Ontario continues to see a weather tug-of-war between cold Arctic air and milder systems pushing in from the west.
Today’s Weather Overview
Current Conditions
Observed at Thunder Bay Airport at 7:00 AM EDT:
Condition: Mostly Cloudy
Temperature: 1.5°C
Wind: West 11 km/h
Humidity: 66%
Pressure: 101.1 kPa and falling
Visibility: 32 km
Today will remain cloudy with a 40 percent chance of flurries or rain showers, transitioning mainly to rain showers this afternoon. Winds become northwest at 20 km/h later today.
Expected High: 7°C
UV Index: 4 or moderate
The morning still carries a winter-like feel, especially in exposed areas near Lake Superior.
Tonight’s Forecast
Cloudy skies continue tonight with a 40 percent chance of showers early this evening before conditions gradually settle overnight.
- Low: -2°C
- Wind Chill: Near -5 overnight
Drivers should watch for isolated icy patches overnight, especially on bridges and elevated surfaces.
Friday Forecast – Finally a Taste of Spring
Friday finally brings more sunshine to the region.
Friday, May 8
- Mainly sunny
- High of 13°C
- UV index 5 or moderate
It will be one of the warmest and brightest days Thunder Bay has seen in quite some time.
Friday night, however, remains unsettled:
- Cloudy periods
- 40 percent chance of rain showers or flurries
- Low near 0°C
Weekend Outlook
Saturday, May 9
- Mix of sun and cloud
- 30 percent chance of rain showers or flurries
- High 9°C
Sunday, May 10
- Continued chance of rain showers or flurries
- High near 9°C
Spring warmth remains inconsistent as cooler air continues to flow off Lake Superior.
Early Next Week
A more stable warming trend appears possible by Monday and Tuesday:
- Monday: Mix of sun and cloud, high 12°C
- Tuesday: Chance of showers, high 14°C
- Wednesday: Mix of sun and cloud, high 15°C
Wardrobe Recommendations
Thunder Bay residents are still dressing for multiple seasons in one day:
- Winter jacket for mornings
- Layers for afternoon warming
- Waterproof footwear remains a smart choice
- Sunglasses likely required Friday afternoon
Gardening & Outdoor Tips
Gardeners should continue delaying planting of frost-sensitive vegetables and flowers. Overnight temperatures below freezing remain possible through the weekend.
A good strategy right now:
- Prepare garden beds
- Clean up winter debris carefully
- Avoid disturbing early pollinators and overwintering beneficial insects
Weather Trivia
Thunder Bay’s location beside the cold waters of Lake Superior often delays spring by several weeks compared to inland Northwestern Ontario communities. Even in May, flurries are not unusual.
Summary
Thunder Bay weather outlook for May 7, 2026: Chilly with flurries or rain showers today, freezing temperatures tonight, and warmer sunshine finally arriving Friday.
