Climate almanac
Thunder Bay
Ontario, CA · 48.38°, -89.25°
What is the climate like in Thunder Bay?
The best time to visit Thunder Bay is typically July – August, with trip comfort peaking in July (7.0/10). Thunder Bay is warmest in July, when daily highs average 74°F (23°C), and coolest in January, when lows fall to about 4°F (-16°C). The wettest month is typically September and the driest is January; the year sees roughly 28 in of precipitation.
- Best time to visitJuly – August — comfort peaks in July (7.0/10)
- Warmest monthJuly — average high 74°F (23°C)
- Coolest monthJanuary — average low 4°F (-16°C)
- Wettest monthSeptember (3.2 in)
- Driest monthJanuary (1.3 in)
- Annual precipitation28 in