Cool
Average highs are around 17°C, so pack for cooler days.
September verdict
Thunder Bay, Ontario, Canada in September
Weather score27Poor
Poor for holiday weather
Average highs are around 17°C, so pack for cooler days. Sunshine averages 5.3h per day, enough for a balanced month. Rainfall averages 88mm, so some wet days are possible.
September weather
Monthly averages
Temp
17°C
Rain
88mm
Sun
5.3h
Sea
14°C
Weather score
27
Poor
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 88mm, so some wet days are possible.
Some sun
Sunshine averages 5.3h per day, enough for a balanced month.
Cool sea
Sea temperatures average 14°C, so the water can feel cool.
Map
Weather map
Compare Thunder Bay, Ontario, Canada with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September17°C average high
September sits in the warmer part of the year, so midday sightseeing can feel heavier than in cooler months.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
September88mm average rain
September is one of Thunder Bay's wettest months, so rain is likely to be a major planning factor.
Driest monthsJanuary to April and November to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September5.3 hours average sun
September sits close to Thunder Bay's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsMay to August
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September14°C average sea
September sits in the warmer sea-temperature season, usually making swimming easier to enjoy.
Warmest seaAugust to September
Sea temperatures are usually near 16°C in this stretch, so swimming comfort is at its strongest.
Weather score
September27 weather score
September is one of the weakest weather-score months, when the overall mix is less favourable than the rest of the year.
Best weather monthsJuly to August
These months have the strongest weather score in the monthly averages.
