Warsaw weather in September
In September, Warsaw has an average high of 20 °C68 °F and an average low of 9 °C49 °F, with about 52 mm2.0 in of precipitation. It is the 4th warmest month of the year and ranks 5th for precipitation.
How September compares with other months
Compared with August, September is 5.3 °C9.6 °F cooler on average and drier by 10 mm0.4 in. Compared with October, September is 6.3 °C11.3 °F warmer on average. Daylight lasts about 12.6 hours around the middle of the month. Average relative humidity is 72% and the average cloud amount 61%.
Is September a good time to visit Warsaw?
Yes — September is one of the most comfortable months to visit Warsaw by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in September
For Warsaw in September, pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
September in nearby places
Other months in Warsaw
- January−1 °C30 °F / −7 °C20 °F
- February1 °C34 °F / −6 °C22 °F
- March7 °C45 °F / −2 °C28 °F
- April14 °C58 °F / 3 °C38 °F
- May20 °C68 °F / 9 °C48 °F
- June24 °C74 °F / 13 °C55 °F
- July26 °C79 °F / 15 °C60 °F
- August26 °C78 °F / 14 °C58 °F
- September20 °C68 °F / 9 °C49 °F
- October13 °C55 °F / 4 °C39 °F
- November6 °C44 °F / 1 °C33 °F
- December1 °C34 °F / −4 °C25 °F
Frequently asked questions
How warm is Warsaw in September?
In September the average high in Warsaw is 20 °C (68 °F) and the average low is 9 °C (49 °F).
Does it rain a lot in Warsaw in September?
On average about 52 mm (2.0 in) of precipitation falls in September; it ranks 5th of the 12 months.
Is September the warmest month in Warsaw?
No. The warmest month in Warsaw is July, with an average high of 26 °C (79 °F). The coldest month is January, with an average low of -7 °C (20 °F).
How long is the day in Warsaw in September?
In the middle of September the day in Warsaw lasts about 12.6 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Warsaw in September?
The average relative humidity in September is about 72%. This is a long-term average for the whole day.
How cloudy is Warsaw in September?
On average about 61% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.