THUNDER BAY – WEATHER NEWS – Thunder Bay’s weather alert has been upgraded, with Environment Canada now listing a Yellow Warning – Rainfall for the city. The impact level is High, with moderate forecast confidence, as heavier rainfall totals are now expected.
Some rural areas of Thunder Bay are already experiencing washouts and road closures as a result of rainfall and spring melt.
Road crews are actively monitoring conditions and responding where needed. Some roads may be temporarily closed or restricted until water levels recede and repairs can be completed.
For more information or to report washouts, residents can contact City Dispatch at (807) 625-2195.
There is a Flood Watch in effect. The Lakehead Region Conservation Authority report is here.
Current Conditions
As of 10:00 AM EDT Monday, April 27, 2026, Thunder Bay Airport reported mostly cloudy skies and a temperature of 5.7°C.
Winds were from the ENE at 24 km/h, gusting to 45 km/h, with pressure at 101.4 kPa and falling. Humidity was 77%, and visibility remained good at 32 km.
Rainfall Warning
Rain, at times heavy, is expected to begin this afternoon or early evening and diminish Tuesday morning.
Environment Canada now expects 25 to 40 mm of rain. The frozen or nearly saturated ground has a reduced ability to absorb this rainfall.
Localized flooding is possible, and some roads may become impassable. Residents are urged to use caution when travelling, obey all posted signs and barricades, and avoid driving through flooded or washed-out areas.
Forecast
Today will be cloudy with a 40 percent chance of showers this morning and early afternoon. Rain begins this afternoon, with 5 to 10 mm possible. East winds will gust to 40 km/h, and the high will reach 8°C.
Tonight brings steady rain, with 10 to 20 mm expected. Winds will shift northwest at 30 km/h, gusting to 50 before morning. The low will be 3°C.
Tuesday will see rain ending in the morning, then mainly cloudy skies with a 40 percent chance of rain showers or flurries. Northwest winds will gust to 50 km/h, with a high of 7°C.
Wardrobe Recommendations
Wear a waterproof jacket, warm layers, and water-resistant footwear. Gusty winds will make umbrellas less effective. Drivers should allow extra travel time and avoid low-lying flooded areas.
Weather Trivia
Thunder Bay’s location along Lake Superior can enhance spring rainfall systems. Cold lake air, saturated ground, spring melt, and slow-moving fronts can combine to raise flooding concerns quickly.
Weather Overview:
Thunder Bay weather update for April 27, 2026: Yellow Rainfall Warning upgraded with 25–40 mm of rain expected as rural washouts and road closures are reported.
