Thunder Bay weather in July

In July, Thunder Bay sees average daytime highs of 22°C and overnight lows near 14°C, with 76 mm of rain across 10.6 wet days and about 15.5 hours of daylight. It is the 1st-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 21°C in the first days to 23°C by the end. The sky is clear or mostly clear about 28% of the time in July, and the air most often feels dry.

Daylight stretches from about 15 h 48 min at the start of July to 14 h 54 min by month's end. Set against the rest of the year, July is Thunder Bay's 2nd-clearest and 10th-windiest month. For the whole year in context, see Thunder Bay's year-round climate.

Daytime high
22°
1st warmest
Overnight low
14°
12th coldest
Rainfall
76 mm
10.6 wet days
Daylight
15 h 30 min
5:17 AM – 8:48 PM
Cloud cover
59%
2nd clearest
Wind
11 km/h
10th windiest
Solar energy
5.93 kWh/m²
Travel score
6.6
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 July

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 21°C in the first days to 23°C by the end.

A typical July day in Thunder Bay reaches about 22°C in the afternoon and slips back to 14°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 18°C and 27°C. Set against its neighbours, July runs about 4°C warmer than June and on par with August.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12113
22113
32113
42113
52213
62213
72213
82213
92214
102214
112214
122214
132214
142214
152214
162314
172314
182314
192314
202314
212314
222314
232314
242314
252314
262314
272314
282314
292314
302314
312314

How July really feels in Thunder Bay

Once humidity and wind are folded in, July averages 0 days that feel above 32°C and 0 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
0
wind chill below the day's low

July sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Thunder Bay weather by month

How July compares with the rest of the year at a glance. July is the 1st-warmest and 2nd-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 July

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in July.

Beyond those clear spells, partly cloudy skies cover about 23% of July, with mostly cloudy or overcast conditions the remaining 49%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14654
24654
34654
44654
54753
64852
74852
84852
94951
104951
115050
125050
135149
145149
155248
165347
175248
185347
195347
205347
215347
225446
235446
245347
255446
265446
275446
285446
295545
305644
315644

Chance of precipitation in July

Any precipitation

Thunder Bay gets around 76 mm of rain over 10.6 wet days in July. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 34% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
135
235
335
436
536
636
736
836
936
1036
1136
1236
1336
1435
1535
1634
1734
1834
1934
2033
2133
2233
2333
2433
2532
2632
2732
2831
2931
3031
3131

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the dry band about 40% of days. Sticky, muggy-or-worse air turns up on roughly 5% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
153311510
251321520
350321620
449321620
548331620
647331730
746331730
845341840
944341840
1042351850
1141351850
1240361950
1339361960
1438361960
1538361960
1637361971
1736362071
1836372071
1935372071
2035372171
2135372171
2235372171
2335372171
2435362171
2536362160
2636352260
2737352260
2838342260
2938342260
3039332260
3139332260

Wind in July

Winds average 11 km/h in July.

Across July, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in July

DaylightNight

Daylight runs from about 15 h 48 min at the start of July to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 54 minutes over July. Sunrise moves from 5:05 AM to 5:35 AM, and sunset from 8:56 PM to 8:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.85:058:56
215.85:068:55
315.85:068:55
415.85:078:55
515.85:088:55
615.85:088:54
715.75:098:54
815.75:108:53
915.75:118:53
1015.75:118:52
1115.75:128:52
1215.65:138:51
1315.65:148:50
1415.65:158:50
1515.55:168:49
1615.55:178:48
1715.55:188:47
1815.55:198:46
1915.45:208:46
2015.45:218:45
2115.45:228:44
2215.35:248:43
2315.35:258:41
2415.25:268:40
2515.25:278:39
2615.25:288:38
2715.15:308:37
2815.15:318:35
2915.05:328:34
3015.05:338:33
3114.95:358:31

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 5.93 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 — July's 5.93 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.0Intense
46.0Intense
56.0Intense
66.0Intense
76.0Intense
86.0Intense
96.0Bright
106.0Bright
116.0Bright
126.0Bright
136.0Bright
146.0Bright
156.0Bright
166.0Bright
176.0Bright
185.9Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in July

Is July a good time to visit Thunder Bay?

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

6.6
Sightseeing
2nd-best month of the year
4.7
Beach & pool
1st-best month of the year

July is a reasonable time to visit Thunder Bay for sightseeing.

What to pack for Thunder Bay in July

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

In July, Thunder Bay sees daytime highs around 22°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 11 days see rain.

light clothesrain gearsun protection

Sea temperature near Thunder Bay in July

The nearest coast averages about 9°C in July — 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 July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks around 6 — enough to warrant sun protection. 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
July 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).