Thunder Bay weather for August 30 to September 1, 2026

August 30, 2026: Thunder Bay Three-Day Forecast — Cool Sunday, Stormy Monday, Warmer Tuesday
THUNDER BAY – WEATHER – Sunday, August 30, 2026 – Thunder Bay starts the final Sunday of August under mostly cloudy skies, with a cool east wind developing and a daytime high near 20°C. The weather turns more unsettled tonight and Monday as showers and thunderstorms move through the area.
Tuesday brings a significant improvement, with a mix of sun and cloud and a high of 26&de