Thunder Bay starts Monday mild but unsettled, with mostly cloudy skies, gusty southwest winds, and falling pressure. Showers are expected today before colder air arrives tonight, changing rain showers to flurries.

Today’s Weather Overview

Current Conditions

Observed at Thunder Bay Airport at 6:00 AM EDT:

Condition: Mostly cloudy
Temperature: 12.8°C
Wind: SSW 23 km/h, gusting to 36
Humidity: 38%
Pressure: 98.6 kPa and falling
Visibility: 24 km

Today brings showers, with winds becoming west at 30 km/h, gusting to 60 this morning. High 13°C. UV index 2, or low.

Tomorrow’s Forecast

Expected Conditions

Tonight: Rain showers change to a few flurries late this evening. Northwest wind 30 km/h, gusting to 60. Low 0°C.

Tuesday, May 5: Mainly cloudy with a 40% chance of flurries in the morning. Northwest wind 20 km/h. High 7°C.

Tuesday Night: Cloudy periods with a 30% chance of flurries or rain showers. Low -2°C.

Wardrobe Recommendations

Wear a rain jacket and secure loose outdoor items before winds strengthen. By tonight, switch back to colder-weather layers as temperatures fall toward freezing and flurries return.

Weather Trivia

Thunder Bay can swing from double-digit temperatures to flurries in the same day during spring, especially when a strong wind shift brings colder air in behind a low-pressure system.

Overview

Thunder Bay weather for May 4, 2026: Showers and gusty winds today, high 13°C, with rain changing to flurries tonight as colder air returns.