Thunder Bay – Weather – A stretch of calm and seasonally mild fall weather will dominate Thunder Bay and the surrounding Lake Superior basin through the final days of October.
Temperatures will hover near or slightly above seasonal averages, with daytime highs mostly between 9 and 12°C, and overnight lows ranging from plus 3 down to minus 2°C.
Light winds and high pressure will keep conditions stable for much of the period, though a weak disturbance midweek may bring brief cloudier periods and a small chance of showers. Overall, it’s a pleasant and tranquil stretch for late October, offering bright days, crisp nights, and little threat of precipitation or severe weather.
Tuesday, October 28
Thunder Bay will wake up to mainly cloudy skies and light easterly winds early in the day. As the morning progresses, a few sunny breaks are expected, especially inland from the lake. Temperatures will climb to a high near 10°C, which is close to normal for this time of year.
Winds will remain light from the southeast at 15 to 20 km/h, keeping conditions calm and cool along the lakeshore.
By evening, skies will gradually clear, setting up a cool and dry night. The temperature will dip to around plus 3°C overnight, with patchy fog possible in sheltered valleys and near river systems.
Wednesday, October 29
A beautiful autumn day is in store with sunny skies and light winds. High pressure will sit directly over northwestern Ontario, bringing clear, calm conditions throughout the region.
Expect a high of 12°C, with light variable winds under 15 km/h.
Overnight, the sky will remain clear, and radiational cooling will drop the temperature to minus 1°C by morning. Rural and low-lying areas could see patchy frost, but road conditions should remain dry.
Thursday, October 30
The weather pattern begins to shift slightly as another weak system approaches from the northwest. Morning sunshine will give way to increasing cloudiness through the afternoon. There is a 30 percent chance of light showers, mainly late in the day or evening, though rainfall amounts are expected to be minimal.
Winds will shift to the south at 20 km/h, keeping the temperature near 9°C through the day. Overnight, skies will be partly to mostly cloudy, and temperatures will hold around plus 2°C, preventing frost formation.
Friday, October 31 – Halloween Day
Halloween looks pleasant and seasonally cool for Thunder Bay residents. Expect a mix of sun and cloud through the day with light westerly winds. Afternoon highs will reach around 8°C, and by trick-or-treat time, temperatures will cool to about plus 2°C — crisp but comfortable for late October.
The night will stay partly cloudy and dry, with a low near plus 1°C. Visibility should be good for evening travel and events, and no precipitation is expected to affect festivities.
Outlook Beyond Friday
Early indications for the first weekend of November point toward a continued stable pattern with temperatures remaining slightly above normal. Daytime highs may reach the low teens again under mostly clear skies. A potential weak front may arrive late Sunday or Monday, bringing the next chance of rain or flurries as cooler air returns to northwestern Ontario.
Summary
-
Temperature Trend: Near seasonal, mild days and cool nights.
-
Precipitation: Minimal — isolated light showers possible Thursday.
-
Winds: Generally light, increasing briefly from the south on Thursday.
-
Visibility: Excellent outside of localized morning fog.
-
Best Weather Days: Wednesday and Friday — clear, bright, and calm.
In short:
Thunder Bay residents can look forward to a dry and mild end to October, with crisp mornings, bright afternoons, and calm Halloween weather — ideal for late-season outdoor work, travel, and festive activities.
