June 22, 2026: Thunder Bay Starts Cool and Sunny Before a Mild, Mixed-Sky Monday
Thunder Bay – Weather Desk – Thunder Bay begins Monday with a crisp early-summer chill at 6°C, mainly sunny skies, and calm, fresh air over the city.
The day will warm nicely, with a mix of sun and cloud expected and a high near 21°C. The UV index will reach 7, or high, so sunshine breaks will still require proper sun protection.
Today’s Weather Overview
Current Conditions
As of 6:00 AM EDT at Thunder Bay Airport, the temperature is 6.2°C under mainly sunny skies. The air is fully saturated, with a dew point of 6.2°C and humidity at 100%, giving the morning a damp and chilly feel.
The wind is from the west at 9 km/h, visibility is excellent at 32 km, and the barometric pressure is 101.9 kPa and rising. That rising pressure supports a more settled start to the day.
Today’s forecast calls for a mix of sun and cloud with a high of 21°C. The UV index is 7, rated high.
Extended Forecast
Tonight: Skies will clear, with fog patches developing overnight. The low will fall to 8°C, so expect another cool night.
Tuesday, June 23: The day starts sunny, then becomes a mix of sun and cloud late in the morning. Morning fog patches will dissipate. The high will reach 23°C, with a UV index of 7, or high. Tuesday night turns cloudy with a 40 percent chance of showers and a low of 8°C.
Wednesday, June 24: Clouds return with a 60 percent chance of showers and a cooler high of 17°C. Wednesday night remains unsettled, with cloudy periods, a 40 percent chance of showers, and a low of 8°C.
Thursday, June 25: Expect a mix of sun and cloud with a 40 percent chance of showers and a high near 21°C. Thursday night brings cloudy periods, a 30 percent chance of showers, and a low of 8°C.
Wardrobe Recommendations
Start the day with a light jacket, hoodie, or sweater, especially for early commutes or outdoor work. By afternoon, lighter layers should be comfortable as temperatures climb into the low 20s.
Keep sunglasses and sunscreen handy because of the high UV index. For late tonight and early Tuesday, drivers should be ready for patchy fog, especially in low-lying areas and near cooler, damp ground.
Weather Trivia
Thunder Bay’s cool June mornings are often influenced by nearby Lake Superior, which warms slowly through spring and early summer. Even when afternoons become mild, lake-cooled air can keep early mornings feeling much fresher than inland communities.
