Thunder Bay weather in March

In March, Thunder Bay sees average daytime highs of -1°C and overnight lows near -10°C, with 31 mm of precipitation across 6.8 wet days and about 11.6 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Highs climb over the month, from about -4°C in the first days to 2°C by the end. The sky is clear or mostly clear about 27% of the time in March, and the air most often feels dry.

Daylight stretches from about 10 h 42 min at the start of March to 12 h 30 min by month's end. Set against the rest of the year, March is Thunder Bay's 5th-clearest and 8th-windiest month. For the whole year in context, see Thunder Bay's year-round climate.

Daytime high
-1°
9th warmest
Overnight low
-10°
4th coldest
Precipitation
31 mm
6.8 wet days
Daylight
11 h 36 min
7:20 AM – 6:54 PM
Cloud cover
64%
5th clearest
Wind
12 km/h
8th windiest
Solar energy
4.03 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 March

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about -4°C in the first days to 2°C by the end.

A typical March day in Thunder Bay reaches about -1°C in the afternoon and slips back to -10°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between -8°C and 6°C. Set against its neighbours, March runs about 6°C warmer than February and about 7°C cooler than April.

-20°-10°10°151015202531
Avg high (°C)Avg low (°C)
1-5-14
2-5-14
3-4-14
4-4-13
5-4-13
6-4-13
7-3-13
8-3-12
9-3-12
10-2-12
11-2-11
12-2-11
13-1-11
14-1-10
15-1-10
16-1-10
170-10
180-9
190-9
200-9
211-8
221-8
231-8
241-8
251-7
262-7
272-7
282-7
292-7
302-6
313-6

How March really feels in Thunder Bay

Once humidity and wind are folded in, March 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 March is cold — wind chill drags the overnight "feels like" below the raw low.

Thunder Bay weather by month

How March compares with the rest of the year at a glance. March is the 9th-warmest and 10th-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 March

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in March.

Beyond those clear spells, partly cloudy skies cover about 13% of March, with mostly cloudy or overcast conditions the remaining 60%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24060
34060
44159
54159
64258
74258
84258
94258
104258
114258
124258
134258
144258
154258
164159
174159
184159
194060
204060
214060
224060
233961
243862
253862
263763
273763
283565
293565
303565
313664

Chance of precipitation in March

Any precipitationSnow

Thunder Bay gets around 31 mm of rain and snow over 6.8 wet days in March. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 22% and peaks near 28% on the wettest days, and about 6 days bring snow. The odds climb toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
11819
21819
31819
41919
51919
61919
71918
82018
92018
102018
112018
122118
132118
142118
152218
162218
172218
182218
192318
202318
212318
222418
232418
242519
252619
262620
272720
282720
292721
302821
312821

Humidity in March

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, March 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 March

Winds average 12 km/h in March.

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

051015151015202531
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
512calm
612calm
712calm
812calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812calm
2912calm
3012calm
3112calm

Sunrise & sunset in March

DaylightNight

Daylight runs from about 10 h 42 min at the start of March to 12 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 108 minutes over March. Sunrise moves from 7:50 AM to 6:48 AM, and sunset from 6:30 PM to 7:16 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.77:506:30
210.77:486:32
310.87:466:33
410.87:446:35
510.97:426:37
611.07:406:38
711.07:386:40
811.17:366:41
911.17:346:43
1011.27:326:44
1111.37:306:46
1211.37:286:47
1311.47:266:49
1411.47:246:50
1511.57:226:52
1611.67:206:54
1711.67:186:55
1811.77:166:57
1911.77:136:58
2011.87:117:00
2111.97:097:01
2211.97:077:03
2312.07:057:04
2412.07:037:06
2512.17:017:07
2612.26:597:09
2712.26:567:10
2812.36:547:12
2912.36:527:13
3012.46:507:15
3112.56:487:16

Solar energy in March

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in March, about 4.03 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 — March's 4.03 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
13.4Moderate
23.4Moderate
33.5Moderate
43.5Moderate
53.6Moderate
63.6Moderate
73.7Moderate
83.7Moderate
93.8Moderate
103.8Moderate
113.8Moderate
123.9Moderate
133.9Moderate
144.0Moderate
154.0Bright
164.0Bright
174.1Bright
184.1Bright
194.2Bright
204.2Bright
214.3Bright
224.3Bright
234.3Bright
244.4Bright
254.4Bright
264.4Bright
274.5Bright
284.5Bright
294.6Bright
304.6Bright
314.7Bright
Planning a trip in March

Is March a good time to visit Thunder Bay?

Our two travel scores rate March 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

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

What to pack for Thunder Bay in March

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

In March, Thunder Bay sees daytime highs around -1°C and nights near -10°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 March

The nearest coast averages about 1°C in March — 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 March

LowModerateHighVery highExtreme

Clear-sky midday UV in March peaks around 3. 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
March 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).