THUNDER BAY – WEATHER DESK – Thunder Bay starts Monday under a Yellow Fog Advisory, with dense fog reducing visibility to near zero in some areas.

At 7:00 AM EDT, conditions show fog and 3.4°C, with 100% humidity, east winds at 9 km/h, and visibility down to 0.4 km.

Today’s Weather Overview

Fog patches will dissipate later this morning, though some may linger into early afternoon. Once visibility improves, expect a mix of sun and cloud.

High: 20°C
Showers: 60% chance this afternoon
Thunderstorm Risk: Late this afternoon
UV Index: 7, or high

Tonight and Tuesday

Tonight: Partly cloudy with a 60% chance of showers this evening and after midnight. Risk of a thunderstorm. Low 10°C.

Tuesday: A mix of sun and cloud. High 20°C. UV index 7, or high.

Tuesday Night: Clear. Low 8°C.

Fog Advisory Travel Note

Travel may be hazardous this morning. Drivers should turn on headlights, slow down, and leave extra space between vehicles. Visibility may drop suddenly.

Looking Ahead

Sunshine takes over midweek:

Wednesday: Sunny, high 21°C
Thursday: Sunny, high 21°C
Friday: Sunny, high 24°C
Saturday: Sunny, high 23°C
Sunday: Sunny, high 24°C

Summary

Thunder Bay weather for May 25, 2026: Yellow Fog Advisory this morning, showers and thunderstorm risk this afternoon, then sunny warm weather later this week.