Mostly cloudy skies hit Thunder Bay on Saturday , with brief damp spells at dawn. The lake keeps waterfront chill noticeable while clouds stick around. Sunday brings sharp sun breaks inland. Lake air stays cooler longer than spots farther from the water . Monday brings sharp temp jumps as the heat wave peaks away from Superior. Lakefront areas see relief while inland spots bake. Local forecasters issued this outlook on July 12, 2026. A sunny Sunday follows the week’s damp start.