Weather in Thunder Bay, Ontario, Canada for the month
The full August calendar: model forecast through August 27, then the long-term climate normal.
🔮 What August will be like
📅 August calendar2-week forecast →
🌅 August astronomy
📒 Weather diary in Thunder Bay
Ready-made observation table for August: past days are already filled in with weather-station data — for school and beyond. Open the diary →
✉️ Weather forecast by email
Get the forecast for this city by email — every day at 17:00 Moscow time.
FAQ about weather in Thunder Bay ❓
What will the weather be like in August in Thunder Bay?
The forecast part of August is near normal: +18°…+22° by day, no prolonged rain. The second half is shown from the climate normal: on average +22° by day and +15° at night.
When are the best days of August?
The forecast points to 25–26 August: +22°. Models don’t see beyond two weeks — check back, the page updates daily.
How accurate is a monthly forecast?
Honestly: models are reliable up to ~14 days. So through August 27 we show the model forecast, and beyond that — each day’s climate normal from long-term observations (ERA5). It is a statistical expectation, not a guarantee.
Weather in Thunder Bay — in detail
Weather forecast in Thunder Bay for the month: from +10° to +22° day and night. Warmest day — Tuesday, August 18 (up to +22°). Coolest — Thursday, August 20 (+10°). No significant precipitation. Trend: it cools toward the end. See also the forecast for 2 weeks and the weather archive.
To quickly check the weather in Thunder Bay anytime, add the city to favorites — and get a daily forecast by email at 17:00 (Moscow time). Note: the forecast may be refined as new data arrives. Data: OpenWeather, Open-Meteo, met.no.