Thunder Bay weather for September 6-8, 2026

September 6-8, 2026: Thunder Bay Forecast — Sunny Sunday Gives Way to a Wet Labour Day and Showery Tuesday
THUNDER BAY – WEATHER – Sunday, September 6, 2026 – Thunder Bay gets one more pleasant late-summer day Sunday before conditions become increasingly unsettled for Labour Day Monday and Tuesday.
Environment Canada is forecasting a sunny 23°C Sunday, followed by clouds, showers and a thunderstorm risk overnight. Labour Day Monday cools to 21°C with a 40 percent