Thunder Bay, Unorganized is among the frostiest of Canadian towns
Sunny July days climb to about 24.9°C. A year here swings 44°C from midwinter lows to midsummer highs. Rain and snow together come to less here than on 66% of Canadian towns. Plan for rain or snow on about 110 days a year, the days with 1 mm or more.
Thunder Bay, Unorganized has no ECCC normals station of its own: every figure here comes from Thunder Bay, 28 km south.
A year in Thunder Bay, Unorganized at a glance
Each month’s typical high and low, in °C.
What stands out about Thunder Bay, Unorganized’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Thunder Bay, Unorganized feels like
Typical highs and lows by season and by month, from ECCC’s 1991–2020 normals.
Frost on about 206 days a year
The frost season runs September to May, and January freezes nearly every night. Deep cold, under −20°C, comes on about 42 nights a year.
Frost days by month
Average days at 0°C or below
About 790 mm of rain and snow a year
July brings the most rain and snow; February, the least.
Rain and snow by month
Millimetres
Thunder Bay publishes no full year of precipitation, so these figures come from Atikokan, 163 km away.
Living with Thunder Bay, Unorganized’s climate
Gardening, time outside, winter cold and summer heat, from the 1991–2020 normals.
For long days outdoors, Jul and Aug bring highs of 17–27°C and lows of 8°C or more.
Parks & trails →About 68 days a year bring a wind chill under −20, when bare skin chills fast.
Roughly 26 days a year feel hotter than 30 once humidity is counted.
For the weather that does damage, from ice storms to floods, see Thunder Bay, Unorganized’s hazards page.
Flood & hazards →ECCC’s normals location: Thunder Bay
ECCC builds the Thunder Bay normals from 4 stations’ records over 1991–2020, joined where one replaced another.
| Distance from the town | 28 km south |
| Station altitude | 199 m |
| Completeness | at least 20 years |
| WMO standard normals | No |
| Precipitation from | Atikokan, 163 km |
| Snowfall from | No location within 100 km |
| Coldest reading, 1991–2020 | −43.2°C |
| Hottest reading, 1991–2020 | 39.0°C |
| Average wind | 11.6 km/h on average, most often from the west |
| Next-nearest location | Atikokan, 163 km |
How Thunder Bay, Unorganized compares
Compared with 2,611 towns and neighbourhoods of 2,500 or more across Canada; the dots mark the other normals locations in Ontario.
Nearby towns’ climate
The nearest places on a normals location of their own: those that share Thunder Bay, Unorganized’s would only repeat its figures. The nearest place to Thunder Bay, Unorganized with figures is 157 km away.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Thunder Bay, Unorganized Thunder Bay | 24.9°C | −19.2°C | 790 mm |
| Schreiber 157 km · Geraldton | 23.6°C 1.3°C cooler | −24.7°C 5.5°C colder | 762 mm |
Thunder Bay, Unorganized weather by month
Average daily high and low, mean temperature and precipitation by month, 1991–2020.
| Month | High | Low | Mean | Rain & snow |
|---|---|---|---|---|
| January | −7.6°C | −19.2°C | −13.4°C | 33 mm |
| February | −5.2°C | −18.3°C | −11.8°C | 26 mm |
| March | 1.0°C | −11.8°C | −5.4°C | 34 mm |
| April | 8.9°C | −4.2°C | 2.4°C | 53 mm |
| May | 15.9°C | 1.9°C | 8.9°C | 80 mm |
| June | 21.6°C | 7.8°C | 14.8°C | 101 mm |
| July | 24.9°C | 11.0°C | 18.0°C | 117 mm |
| August | 24.2°C | 10.0°C | 17.1°C | 94 mm |
| September | 19.2°C | 5.5°C | 12.4°C | 102 mm |
| October | 10.9°C | −0.3°C | 5.3°C | 74 mm |
| November | 2.6°C | −6.7°C | −2.1°C | 40 mm |
| December | −4.5°C | −14.6°C | −9.6°C | 38 mm |
| Year | 9.3°C | −3.3°C | 3.0°C | 790 mm |
The month with the widest range: March, −34.7°C to 23.9°C
Bars run from each month’s record low to its record high over 1991–2020; February is the month whose average wanders most from year to year (±3.7°C around −11.8°C), June the one that wanders least (±1.0°C).
Where Thunder Bay, Unorganized’s numbers come from
Averages over 30 years, not a forecast.
- Normals: the Canadian Climate Normals, 1991–2020, at Thunder Bay (the closest location with all twelve months of temperatures).
- Other locations: where a location publishes no full year of precipitation or snowfall, the nearest one that does supplies it, named beside those figures.
- Comparisons: every Canadian town and neighbourhood of 2,500 or more, each read from its own nearest location; city totals and reserves are left out.
- Not on this page: snow, with no complete snowfall normals within 100 km, sunshine, which ECCC published for no location, and any height adjustment.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Thunder Bay, Unorganized’s climate
How warm does Thunder Bay, Unorganized get in summer?
A normal July afternoon tops out at about 24.9°C, the year’s high point.
How cold does Thunder Bay, Unorganized get in winter?
Winter bottoms out in January, with lows near −19.2°C.
How much rain and snow does Thunder Bay, Unorganized get?
Count on roughly 790 mm a year, heaviest in July (117 mm) and lightest in February (26 mm).
Are these figures for Thunder Bay, Unorganized itself?
They are the closest available: the normals for Thunder Bay, since Thunder Bay, Unorganized has none.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Thunder Bay, Unorganized →
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).