Cool
Average highs are around 10°C, so pack for cooler days.
September verdict
Posio, Finland in September
Weather score22Poor
Poor for holiday weather
Average highs are around 10°C, so pack for cooler days. Sunshine averages 3h per day, so this is not one of the brighter months. Rainfall averages 60mm, which is relatively low for holiday planning.
September weather
Monthly averages
Temp
10°C
Rain
60mm
Sun
3h
Weather score
22
Poor
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 60mm, which is relatively low for holiday planning.
Limited sun
Sunshine averages 3h per day, so this is not one of the brighter months.
Map
Weather map
Compare Posio, Finland with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September10°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 August
This stretch sets the upper range for average daytime heat.
Rain
September60mm average rain
September is wetter than Posio's yearly average, so flexible plans matter more.
Driest monthsJanuary to June and September to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September3 hours average sun
September sits close to Posio's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsMay to July
This stretch has the strongest sunshine in the monthly averages.
Weather score
September22 weather score
September scores below Posio's yearly average, so the weather trade-offs are more noticeable.
Best weather monthsJune to July
These months have the strongest weather score in the monthly averages.