THUNDER BAY – WEATHER – After a weekend that had wild winds, serious rain, power outages, it is a far more pleasant start for Monday.

Thunder Bay is starting the day with mild temperatures and calm winds under partly cloudy skies. Conditions will be mainly sunny through most of the day, but an approaching system will bring a chance of showers and thunderstorms before morning, along with local smoke.

Today’s Weather Overview

Current Conditions (7:00 AM EDT – Thunder Bay Airport)

• Temperature: 16.1°C

• Humidity: 100%

• Dew Point: 16.1°C

• Wind: SSW 5 km/h

• Pressure: 101.3 kPa, falling

• Visibility: 32 km

• Sky: Partly cloudy

Daytime Forecast

• Conditions: Mainly sunny, fog patches dissipating early.

• Wind: Becoming southwest 20 km/h this afternoon.

• High: 27°C

• Humidex: 32 (feels hotter due to humidity)

• UV Index: 7 – High (sun protection recommended)

Tonight

• Conditions: Clear this evening, then partly cloudy before morning with 60% chance of showers and risk of thunderstorms. Local smoke possible.

• Low: 17°C

Tomorrow’s Forecast – Tuesday, August 12, 2025

• Daytime: Mainly cloudy, 60% chance of showers and risk of a thunderstorm.

• Wind: Becoming west 30 km/h gusting to 50 in the morning.

• High: 23°C

• Humidex: 27

• UV Index: 6 – High

Night: Cloudy periods with 30% chance of showers. Low 11°C.

Wednesday, August 13, 2025

• Daytime: Mix of sun and cloud. High 21°C.

• Night: Cloudy periods. Low 9°C.

Wardrobe Recommendations

• Today: Light summer clothing for warm and humid conditions, with sunglasses and sunscreen for high UV.

• Tonight: Keep a light jacket handy; possible showers or thunderstorms before morning.

• Tuesday: Dress in light layers to handle cooler breezy conditions, but be ready for passing showers.

Weather Trivia

On August 11, 1985, Thunder Bay saw an afternoon high of 31.7°C, only to drop to 17°C by evening after a powerful storm front passed through. It’s a reminder of how quickly summer weather can shift along Lake Superior.