AI-generatedThunder Bay at a glance
- Best time
- Jun – Sep
- Warmest month
- Jul · 22°
- Sunshine a year
- 2,150 h
- Rain a year
- 705 mm
- Climate
- Continental
- Time zone
- UTC−5 / UTC−4
- Elevation
- 188 m
Climate in Thunder Bay
Thunder Bay has warm to hot summers and cold winters with occasional snow. July is the warmest month with average highs of 22 °C, while January is the coolest at −9 °C. With around 2,150 hours of sunshine a year, Thunder Bay is moderately sunny; July is the sunniest month with 8.9 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Poor
Best time to visit: June – September
A typical day in October
- Morning, 08:00: about 6°
- Midday, 13:00: about 9°
- Afternoon, 16:00: about 10°
- Evening, 20:00: about 8°
- Night, 23:00: about 7°
08:1519:10
Cold evenings: bring a warm jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:56–08:58 · evening 18:28–19:30
- Blue hour
- Morning 07:43–07:56 · evening 19:30–19:42
Golden hour: the sun between 4° below and 6° above the horizon; blue hour: 6° to 4° below it. Times for the 15th of the month; mountains and clouds shift the light.
What is the weather like in Thunder Bay in October?
In October, Thunder Bay is cool: daytime highs average 10 °C, and nights cool down to about 6 °C. Expect around 4 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 79 mm in total. All in all, October is not an ideal month for a holiday in Thunder Bay.
More details for October
- Daylight
- 10 h 55 min08:15 – 19:10
- UV index
- 2 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 25 km/haverage daily peakAll months
- Cloud cover
- 67 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 1 day1 cm or more of fresh snowAll months
- Time zone
- UTC−4America/Toronto
How the score comes together
- Temperatureweight 50 %21 %
- Sunshineweight 20 %17 %
- Few rainy daysweight 30 %54 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in October
- A jumper for the evenings
- Rain jacket or umbrella
Sunshine hours in Thunder Bay
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 4.0 of 10.9 hours of daylight in Thunder Bay, 37 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in Thunder Bay
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 2 · lowLittle protection needed; sunglasses on bright days.
The sun is strongest in June (UV 8).
Minutes until sunburn in October
- Very fair skin
- about 55 min
- Fair skin
- about 70 min
- Light brown skin
- about 95 min
- Olive skin
- over 2 h
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in Thunder Bay: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, Thunder Bay has about 10 rainy days with 79 mm of rain in total.
Wind and clouds in Thunder Bay
How breezy and how cloudy Thunder Bay is through the year. Tap a month to select it on the whole page.
Wind
Typical daily peak of the wind in km/h: what the afternoon breeze usually reaches, not the gusts.
In October, the wind in Thunder Bay typically peaks at 25 km/h during the day: Beaufort 4, moderate breeze.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 67 % of the sky over Thunder Bay: mostly cloudy, with about 4.0 hours of sunshine a day.
Wind: mean daily maximum of the hourly wind 10 m above ground (ERA5, 1996–2025). Gusts are stronger, and the model grid of about 28 km smooths out local effects such as capes and valley winds. Clouds: mean total cloud cover of all layers over day and night (ERA5, 1996–2025). Thin high cloud counts as cover even when the sun still shines through.
Snow in Thunder Bay
When Thunder Bay is likely to be white: the chance of seeing snow during a week's stay, the days with fresh snow and how much falls. Tap a month to select it.
Snow calendar
- hardly any
- possible
- likely
- very likely
In October, Thunder Bay has about 1 days with at least 1 cm of fresh snow, 2 cm in total. The chance of seeing snow during a week's stay is 10 out of 100: hardly any.
Snow days bring at least 1 cm of fresh snow. Fresh snow comes from ERA5 snowfall (1996–2025) at the height of the place, not on the slopes above it; the snow chance also weighs whether the snow settles. An estimate from climate averages, not a snow report.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Thunder Bay
How warm the nights get in each month, from the mean night-time low. Tap a month for details.
- Frost below 0°
- Cold 0–8°
- Cool 8–15°
- Pleasant 15–20°
ColdOctober: nights around 6°. The room should be heated.
The coolest nights are in January (−15°), the warmest in August (16°). Nights are pleasant for sleeping (15 to 20 °C) from July to August. Nights fall below 8 °C on average from October to May, so the room should be heated.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|
| JanuaryJan | 26 | −9° | −15° | 3.6 h | 7 | 31 |
| FebruaryFeb | 33 | −8° | −14° | 5.1 h | 6 | 27 |
| MarchMar | 33 | −2° | −8° | 6.1 h | 7 | 39 |
| AprilApr | 34 | 4° | −2° | 7.2 h | 9 | 64 |
| MayMay | 46 | 11° | 4° | 8.0 h | 10 | 69 |
| JuneJun | 79 | 17° | 11° | 8.6 h | 11 | 74 |
| JulyJul | 86 | 22° | 16° | 8.9 h | 10 | 70 |
| AugustAug | 83 | 22° | 16° | 7.8 h | 10 | 68 |
| SeptemberSep | 75 | 18° | 13° | 6.0 h | 10 | 84 |
| OctoberOct | 30 | 10° | 6° | 4.0 h | 10 | 79 |
| NovemberNov | 20 | 3° | −2° | 2.7 h | 9 | 55 |
| DecemberDec | 21 | −4° | −11° | 2.7 h | 8 | 46 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences
48.38° N, 89.25° W · 188 m · America/Toronto
Best time to visit Thunder Bay
The best time to visit Thunder Bay is from June to September. For sightseeing, day trips and hiking, conditions are most comfortable from June to September. The wettest month is September with 84 mm of precipitation.
Thunder Bay through the seasons
How the weather changes over the seasons, with averages for each.
Thunder Bay in spring
Mar – May
Poor
- -2–11 °C by day
- 7 h of sun a day
- 26 rainy days in all
Thunder Bay in summer
Jun – Aug
Excellent
- 17–22 °C by day
- 8 h of sun a day
- 31 rainy days in all
Thunder Bay in autumn
Sep – Nov
Fair
- 3–18 °C by day
- 4 h of sun a day
- 29 rainy days in all
Thunder Bay in winter
Dec – Feb
Poor
- -9–-4 °C by day
- 4 h of sun a day
- 21 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in Thunder Bay for you.
Your best months: July – August
Based on the climate averages; tap a month to see its details.
Compare two months in Thunder Bay
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
July has the better holiday weather in Thunder Bay: score 86 against 30. In July, days are 12 °C warmer than in October. The sun shines 5 hours longer a day in July.
| Month | October | July |
|---|---|---|
| Weather score | 30 | 86better |
| Day high | 10° | 22° |
| Night low | 6° | 16° |
| Sunshine | 4.0 h | 8.9 hbetter |
| Rainy days | 10 | 10 |
| Rainfall | 79 mm | 70 mm |
| Muggy days | 0better | 3 |
Based on the climate averages 1996–2025.
Which month for what?
Beach & swimming
No sea nearby
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
Jun – Sep
15–28 °C and not too much rain
Snow
Nov – Apr
Snow on 2 or more days
Thunder Bay month by month
The typical weather for every month at a glance.
26January-9° · 4 h
In January, Thunder Bay is freezing cold: daytime highs average −9 °C, and nights often drop below freezing (−15 °C). The sun is scarce, with only about 4 hours a day. Precipitation, often as snow, falls on about 7 days, totalling 31 mm. Snow falls on about 6 days. All in all, January is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in January33February-8° · 5 h
In February, Thunder Bay is freezing cold: daytime highs average −8 °C, and nights often drop below freezing (−14 °C). Expect around 5 hours of sunshine a day. Precipitation, often as snow, falls on about 6 days, totalling 27 mm. Snow falls on about 5 days. All in all, February is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in February33March-2° · 6 h
In March, Thunder Bay is freezing cold: daytime highs average −2 °C, and nights often drop below freezing (−8 °C). Expect around 6 hours of sunshine a day. Precipitation, often as snow, falls on about 7 days, totalling 39 mm. Snow falls on about 5 days. All in all, March is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in March34April4° · 7 h
In April, Thunder Bay is cold: daytime highs average 4 °C, and nights often drop below freezing (−2 °C). The sun shines for around 7 hours a day. Precipitation, often as snow, falls on about 9 days, totalling 64 mm. Snow falls on about 4 days. All in all, April is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in April46May11° · 8 h
In May, Thunder Bay is cool: daytime highs average 11 °C, and nights cool down to about 4 °C. The sun shines for around 8 hours a day. Rain is frequent, with about 10 rainy days and 69 mm in total. All in all, May is a so-so month for a holiday in Thunder Bay.
Thunder Bay in May79June17° · 9 h
In June, Thunder Bay is mild: daytime highs average 17 °C, and nights cool down to about 11 °C. The sun shines for around 9 hours a day. Rain is frequent, with about 11 rainy days and 74 mm in total. All in all, June is a good month for a holiday in Thunder Bay.
Thunder Bay in June86July22° · 9 h
In July, Thunder Bay is warm: daytime highs average 22 °C, and nights cool down to about 16 °C. The sun shines for around 9 hours a day. Rain is frequent, with about 10 rainy days and 70 mm in total. All in all, July is an excellent month for a holiday in Thunder Bay.
Thunder Bay in July83August22° · 8 h
In August, Thunder Bay is warm: daytime highs average 22 °C, and nights cool down to about 16 °C. The sun shines for around 8 hours a day. Rain is frequent, with about 10 rainy days and 68 mm in total. All in all, August is an excellent month for a holiday in Thunder Bay.
Thunder Bay in August75September18° · 6 h
In September, Thunder Bay is mild: daytime highs average 18 °C, and nights cool down to about 13 °C. Expect around 6 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 84 mm in total. All in all, September is a good month for a holiday in Thunder Bay.
Thunder Bay in September30October10° · 4 h
In October, Thunder Bay is cool: daytime highs average 10 °C, and nights cool down to about 6 °C. Expect around 4 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 79 mm in total. All in all, October is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in October20November3° · 3 h
In November, Thunder Bay is freezing cold: daytime highs average 3 °C, and nights often drop below freezing (−2 °C). The sun is scarce, with only about 3 hours a day. Precipitation, often as snow, falls on about 9 days, totalling 55 mm. Snow falls on about 4 days. All in all, November is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in November21December-4° · 3 h
In December, Thunder Bay is freezing cold: daytime highs average −4 °C, and nights often drop below freezing (−11 °C). The sun is scarce, with only about 3 hours a day. Precipitation, often as snow, falls on about 8 days, totalling 46 mm. Snow falls on about 7 days. All in all, December is not an ideal month for a holiday in Thunder Bay.
Thunder Bay in DecemberThunder Bay compared
Put Thunder Bay side by side with another destination.
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Thunder Bay vs. Sault Ste. Marie
In October the holiday weather in Thunder Bay and Sault Ste. Marie is about equally good (score 30 vs. 33). During the day Sault Ste. Marie is 2 °C warmer than Thunder Bay.
| in October | Thunder Bay | Sault Ste. Marie |
|---|---|---|
| Holiday score | 30 | 33 |
| Daytime high | 10° | 12° |
| Sunshine | 4 h | 4 h |
| Rainy days | 10 | 14 |
| Best time | Jun – Sep | May – Sep |
Through the year
Canada in October: the best places
In October, Thunder Bay ranks 24 among the 31 nearest destinations in this country.
- Hamilton15°53
- 2Toronto14°52
- 3Niagara-on-the-Lake15°51
- 4Niagara Falls15°51
- 5London15°50
- 6Calgary11°48
- 7Collingwood (Blue Mountains)13°47
- 8Ottawa13°44
- 24Thunder BayThis page10°30
Planning a trip to Thunder Bay
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Thunder Bay in the school holidays
How the weather suits the usual holiday periods. Dates vary by school and region, so each holiday uses the months it usually falls in.
Thunder Bay has its best school-holiday weather during the summer holidays (score 84) and its weakest during the Christmas holidays (score 24).
- 34
Easter holidays
Mar – Apr
Poor
- 2 °C by day
- 6.9 h of sun a day
- 8 rainy days a month
Keep in mind: Snow
- 53
May half-term
May – Jun
Fair
- 12 °C by day
- 8.1 h of sun a day
- 10 rainy days a month
- 84
Summer holidays
Jul – Aug
ExcellentBest holidays
- 22 °C by day
- 8.2 h of sun a day
- 10 rainy days a month
Good for: Sightseeing & walks
- 30
October half-term
Oct
Poor
- 10 °C by day
- 4.0 h of sun a day
- 10 rainy days a month
- 24
Christmas holidays
Dec – Jan
Poor
- −7 °C by day
- 3.2 h of sun a day
- 8 rainy days a month
Keep in mind: Snow
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- about 7 h 40 min
- Distance
- 5,960 km
- Time zone
- UTC−4
- Jet lag
- About 3 days (5 h west)
Rule of thumb for flying west: for a few days before, stay up a little later, and get afternoon and evening light at your destination.
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about Thunder Bay
When is the best time to visit Thunder Bay?
The best time to visit Thunder Bay is from June to September. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
What is the warmest month in Thunder Bay?
July is the warmest month, with average highs of 22 °C and nights around 16 °C. January is the coolest month at −9 °C.
When does it rain most in Thunder Bay?
The wettest month is September with 84 mm of precipitation. The driest month is February with 27 mm.
How many hours of sunshine does Thunder Bay get?
Thunder Bay gets around 2,150 hours of sunshine a year. The sunniest month is July with 8.9 hours a day; in November there are 2.7 hours a day.
What time zone is Thunder Bay in?
Thunder Bay uses the time zone America/Toronto: UTC−5 in January and UTC−4 in July.
How long is the flight from London to Thunder Bay?
A nonstop flight from London to Thunder Bay takes about 7 h 40 min, for a straight-line distance of about 5,960 km.
Which school holidays are best for Thunder Bay?
Thunder Bay has its best school-holiday weather during the summer holidays (score 84) and its weakest during the Christmas holidays (score 24). Holiday ratings (0–100): Easter holidays 34, May half-term 53, Summer holidays 84, October half-term 30, Christmas holidays 24.
Near Thunder Bay
Other destinations close by.
Places with a climate like Thunder Bay
Destinations whose weather through the year is closest to Thunder Bay's – good alternatives.