Climate almanac
Thunder Bay
Ontario, Canada · 48.38°, -89.25°
What is the weather like in Thunder Bay in September?
In September, Thunder Bay is typically 64°F (18°C) during the day and 50°F (10°C) at night. The month brings about 3.2 in (81 mm) of precipitation in total.
- Average high64°F (18°C)
- Average low50°F (10°C)
- Precipitation3.2 in (81 mm)
- Clear or mostly clear days9
- Based on2016-2025 daily ERA5 reanalysis data (10-year normals)