Thunder Bay begins October with a mild but windy Thursday, followed by sunny and cooler weather Friday and increasing cloud Saturday
THUNDER BAY – WEATHER – Thursday, October 1, 2026 – Thunder Bay begins October with relatively mild temperatures, but gusty west winds will make their presence felt through the day. A cooler and calmer Friday follows before clouds increase Saturday, bringing another chance of showers by Saturday night.
It is chilly on the fingers for walking or cycling this morning.
Environment Canada is forecasting temperatures above the early-October normal today before a noticeable cooldown heading into the weekend.
Today’s Weather Overview
Current Conditions
At 4:00 a.m. EDT, Thunder Bay Airport was reporting clear skies and a temperature of 11.6°C.
Humidity was 80 per cent, with a dew point of 8.2°C. Winds were from the west-northwest at 10 km/h, while barometric pressure stood at 100.8 kPa and was falling. Visibility was 24 kilometres.
Thursday will become increasingly breezy. Environment Canada calls for a 30 per cent chance of showers early this morning, followed by clearing. West winds will strengthen to 30 km/h, gusting to 50 km/h.
The daytime high will reach 19°C, considerably warmer than Thunder Bay’s seasonal normal high of about 14°C. The UV index will be 4, or moderate.
Tonight will be partly cloudy with a 30 per cent chance of showers overnight. Northwest winds of 20 km/h could gust to 40 km/h. The overnight low will be 8°C.
Tomorrow’s Forecast
Friday, October 2
Friday will deliver the brightest weather of the three-day period.
Environment Canada is forecasting sunny skies with a high of 15°C. Winds are expected to be less of a factor than Thursday.
Friday night will be clear and much colder, with the temperature falling to around 0°C.
Anyone heading out early Saturday morning should be prepared for near-freezing conditions, particularly in lower-lying areas outside the urban core.
Saturday, October 3
Cloud cover will increase Saturday as another weather system approaches Northwestern Ontario.
The daytime high is forecast to reach only 12°C, giving the day a distinctly more autumn-like feel.
Saturday night will remain cloudy with a 40 per cent chance of showers and an overnight low near 4°C.
Wardrobe Recommendations
Thursday will be mild enough for a light jacket during the afternoon, but the strong west winds could make exposed areas feel cooler. A wind-resistant outer layer will be useful, particularly near the waterfront and in open areas.
Friday calls for layers. The afternoon should be comfortable in sunshine, but temperatures will fall quickly after sunset. A warmer jacket will be needed Friday evening as temperatures head toward freezing.
For Saturday, plan on a sweater or fleece beneath a fall jacket. If you will be outdoors Saturday evening, adding a light waterproof shell or carrying an umbrella would be sensible with showers possible overnight.
Weather Trivia
Thunder Bay’s average high for this time of year is approximately 14°C, while the normal overnight low is near 2°C. That makes Thursday’s forecast high of 19°C notably mild for the opening day of October.
The rapidly changing temperatures are typical of Northwestern Ontario in autumn, when warm air moving northward can quickly be replaced by cooler air behind passing weather systems.
