Thunder Bay weather in January

In January, Thunder Bay sees average daytime highs of -10°C and overnight lows near -18°C, with 29 mm of precipitation across 6.5 wet days and about 8.6 hours of daylight. It is the 12th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near -10°C through the month. The sky is clear or mostly clear about 24% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 12 min at the start of January to 9 h 06 min by month's end. Set against the rest of the year, January is Thunder Bay's 9th-clearest and 5th-windiest month. For the whole year in context, see Thunder Bay's year-round climate.

Daytime high
-10°
12th warmest
Overnight low
-18°
1st coldest
Precipitation
29 mm
6.5 wet days
Daylight
8 h 30 min
8:50 AM – 5:22 PM
Cloud cover
67%
9th clearest
Wind
13 km/h
5th windiest
Solar energy
1.53 kWh/m²
Travel score
0.0
out of 10

Thunder Bay is city in Thunder Bay District, Ontario, Canada.

Air quality
Excellent
PM2.5 5 µg/m³ · 2019
Density
243/km²
people per km²
Founded
1683

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near -10°C through the month.

A typical January day in Thunder Bay reaches about -10°C in the afternoon and slips back to -18°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between -19°C and -1°C. Set against its neighbours, January runs about 4°C cooler than December and about 2°C cooler than February.

-30°-20°-10°151015202531
Avg high (°C)Avg low (°C)
1-9-16
2-9-17
3-9-17
4-9-17
5-9-17
6-9-17
7-9-17
8-9-17
9-9-17
10-10-18
11-10-18
12-10-18
13-10-18
14-10-18
15-10-18
16-10-18
17-10-18
18-10-18
19-10-18
20-10-18
21-10-18
22-10-18
23-10-18
24-10-18
25-10-18
26-10-18
27-10-18
28-9-18
29-9-18
30-9-18
31-9-18

How January really feels in Thunder Bay

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
31
31 feel bitter (≤ -10°C)

The story in January is cold — wind chill drags the overnight "feels like" below the raw low.

Thunder Bay weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-10° / -18°296.57.58.60.0
Feb-7° / -16°224.95.49.90.0
Mar-1° / -10°316.85.611.60.0
Apr / -3°548.3513.40.7
May13° / 6610.10.8153.5
Jun19° / 10°6510.5015.85.8
Jul22° / 14°7610.6015.56.6
Aug22° / 13°679.1014.16.7
Sep17° / 8410.5012.45.2
Oct / 7210.41.310.61.7
Nov / -5°497.85.790.0
Dec-6° / -13°387.37.88.20.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 12% of January, with mostly cloudy or overcast conditions the remaining 64%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23466
33565
43565
53664
63664
73565
83565
93664
103664
113664
123664
133664
143664
153565
163565
173664
183664
193664
203763
213763
223763
233763
243763
253763
263862
273862
283763
293763
303763
313862

Chance of precipitation in January

Any precipitationSnow

Thunder Bay gets around 29 mm of rain and snow over 6.5 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 21% and peaks near 23% on the wettest days, and about 8 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12325
22325
32325
42325
52326
62326
72226
82226
92226
102226
112226
122226
132226
142226
152226
162226
172326
182226
192226
202225
212225
222124
232124
242023
252023
261922
271922
281822
291821
301721
311720

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

Most of January feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, January lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in January

Winds average 13 km/h in January.

Across January, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 12 min at the start of January to 9 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 54 minutes over January. Sunrise moves from 8:55 AM to 8:37 AM, and sunset from 5:05 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.28:555:05
28.28:555:06
38.28:555:07
48.28:555:08
58.28:555:09
68.38:555:10
78.38:545:11
88.38:545:12
98.38:545:14
108.48:535:15
118.48:535:16
128.48:535:17
138.48:525:18
148.58:525:20
158.58:515:21
168.58:505:22
178.68:505:23
188.68:495:25
198.68:485:26
208.78:485:28
218.78:475:29
228.78:465:30
238.88:455:32
248.88:445:33
258.98:435:35
268.98:425:36
278.98:415:38
289.08:405:39
299.08:395:41
309.18:385:42
319.18:375:44

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.53 kWh/m².

For context, solar energy here swings from a low near 1.12 kWh/m² to a high of 6.21 kWh/m² in June across the year — January's 1.53 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.2Dim
21.2Dim
31.3Dim
41.3Dim
51.3Dim
61.3Dim
71.3Dim
81.3Dim
91.4Dim
101.4Dim
111.4Dim
121.4Dim
131.4Dim
141.5Dim
151.5Dim
161.5Dim
171.5Dim
181.6Dim
191.6Dim
201.6Dim
211.6Dim
221.7Dim
231.7Dim
241.8Dim
251.8Dim
261.8Dim
271.9Dim
281.9Dim
291.9Dim
302.0Dim
312.0Moderate
Planning a trip in January

Is January a good time to visit Thunder Bay?

Our two travel scores rate January for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.0
Sightseeing
8th-best month of the year
0.0
Beach & pool
7th-best month of the year

January is a weaker month for outdoor sightseeing in Thunder Bay.

What to pack for Thunder Bay in January

From January's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In January, Thunder Bay sees daytime highs around -10°C and nights near -18°C. Pack a warm layer and a heavy coat. About 7 days see rain.

a warm layera heavy coat

Sea temperature near Thunder Bay in January

The nearest coast averages about 2°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 15°C and coldest in March near 1°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

0°5°10°15°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan2Bracing
Feb1Bracing
Mar1Bracing
Apr2Bracing
May3Bracing
Jun4Bracing
Jul9Bracing
Aug15Cool
Sep14Bracing
Oct10Bracing
Nov6Bracing
Dec4Bracing

UV index in Thunder Bay in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Thunder Bay peaks around June 17 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 17UV 8Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May6High
Jun8Very high
Jul6High
Aug6High
Sep5Moderate
Oct3Moderate
Nov1Low
Dec1Low
Location & terrain

Where is Thunder Bay?

Thunder Bay sits at 48.4°N, 89.3°W, 188 m above sea level, in Canada. The nearest listed city is Marquette, 247 km away.

WausauWestonKenoraMarshfield

Topography around Thunder Bay

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Thunder Bay.

Within 3 km, the terrain around Thunder Bay has only modest variations in elevation — a maximum elevation change of 20 m around an average of 188 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 297 m; within 80 km, significant variations in elevation — a maximum elevation change of 503 m.

The land around Thunder Bay is covered by artificial surfaces (41%) and trees (26%) within 3 km, trees (43%) and water (39%) within 16 km, and trees (57%) and water (40%) within 80 km.

3 km
20 m
16 km
297 m
80 km
503 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
January weather nearby: Marquette 247 km · Duluth 278 km · Superior 283 km · Hibbing 295 km · Wausau 382 km · Weston 389 km · Kenora 411 km · Marshfield 419 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Thunder Bay (48.382°, -89.2502°, elevation 188 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).