THUNDER BAY – Thunder Bay is starting Wednesday in a cool, damp pattern, but without any active weather alerts. Environment Canada reports no alerts in effect for the City of Thunder Bay this morning, even as low cloud, lingering moisture, and patchy fog keep the day feeling raw.
Today’s Weather Overview
At 7:00 AM EDT, Thunder Bay Airport was reporting mostly cloudy skies, a temperature of 2.6°C, 100 percent humidity, southwest winds at 7 km/h, and 19 km visibility. Pressure was 101.0 kPa and falling, a sign the atmosphere remains unsettled.
Environment Canada’s forecast says today will stay cloudy, with a 40 percent chance of drizzle early this morning and fog patches dissipating this morning. The daytime high is expected to reach 6°C, with a UV index of 2, or low.
Tonight and the Next Few Days
Tonight stays grey and damp. The forecast calls for cloudy skies, a 30 percent chance of drizzle overnight, a risk of freezing drizzle, and more fog patches, with the low dropping to 0°C.
Thursday looks a little milder, but not much brighter. Thunder Bay is expected to stay cloudy, with a 30 percent chance of drizzle in the morning and another risk of freezing drizzle early in the day. Fog patches should ease in the morning, and the high is forecast to reach 9°C. Thursday night turns to cloudy periods with a low of 2°C.
Friday brings a 40 percent chance of showers and a high of 10°C, but colder air starts to edge back in Friday night with a 70 percent chance of rain showers or flurries and a low of 0°C. Saturday stays cooler, with a 40 percent chance of flurries and a high of 3°C, before sunny weather returns Sunday with a high of 6°C.
Travel and Wardrobe Outlook
This is not a major storm day, but it is still a day for a little caution. The mix of drizzle, fog patches, and near-freezing temperatures tonight could leave some slick spots on untreated surfaces. That is an inference based on the official forecast calling for drizzle, fog, and a freezing drizzle risk.
A waterproof spring jacket and shoes with decent grip are a smart choice today. Heavier layers are not essential this afternoon, but they may still be welcome tonight as temperatures slide back to the freezing mark. This is an inference based on the official temperature and precipitation forecast.
Weather Trivia
Thunder Bay often gets these drawn-out April transitions because Lake Superior helps hold cool, moisture-rich air over the city even when warmer spring air is trying to push in. That is one reason drizzle and fog can linger here longer than in inland parts of northwestern Ontario. This is an inference based on the regional forecast setup.
Overview
Thunder Bay weather update for April 15, 2026: mostly cloudy and damp today with drizzle risk, fog early, and a chance of freezing drizzle tonight before a milder Thursday.
