Saint Petersburg weather in September
In September, Saint Petersburg has an average high of 15 °C59 °F and an average low of 8 °C47 °F, with about 63 mm2.5 in of precipitation. It is the 4th warmest month of the year and ranks 7th for precipitation.
How September compares with other months
Compared with August, September is 5 °C8.9 °F cooler on average and drier by 35 mm1.4 in. Compared with October, September is 7.1 °C12.7 °F warmer on average and drier by 10 mm0.4 in. Daylight lasts about 12.7 hours around the middle of the month. Average relative humidity is 86% and the average cloud amount 70%.
Is September a good time to visit Saint Petersburg?
September is not among the most comfortable months by our comfort score: it is cool (average high 15 °C59 °F) and it is fairly wet (63 mm2.5 in). The most comfortable months in Saint Petersburg are June–August.
What to wear in September
For Saint Petersburg in September, pack long sleeves, a sweater and a medium jacket.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Saint Petersburg | 1559 | 847 | 632.5 |
| Velikiy Novgorod | 1660 | 846 | 662.6 |
| Pskov | 1661 | 847 | 682.7 |
| Lahti | 1558 | 745 | 642.5 |
| Vantaa | 1560 | 847 | 622.4 |
| Helsinki | 1559 | 1253 | 632.5 |
| Petrozavodsk | 1356 | 846 | 712.8 |
| Espoo | 1559 | 1152 | 622.5 |
| Tallinn | 1660 | 1152 | 572.3 |
Nearby places that are more than 1 °C1.8 °F warmer in September: Helsinki, Espoo and Tallinn; cooler: Petrozavodsk.
Other months in Saint Petersburg
- January−6 °C20 °F / −11 °C11 °F
- February−5 °C23 °F / −11 °C12 °F
- March0 °C32 °F / −6 °C21 °F
- April8 °C46 °F / 0 °C32 °F
- May15 °C60 °F / 7 °C44 °F
- June19 °C66 °F / 11 °C52 °F
- July22 °C72 °F / 15 °C58 °F
- August20 °C69 °F / 13 °C55 °F
- September15 °C59 °F / 8 °C47 °F
- October7 °C45 °F / 2 °C36 °F
- November1 °C33 °F / −3 °C27 °F
- December−4 °C25 °F / −8 °C18 °F
Frequently asked questions
How warm is Saint Petersburg in September?
In September the average high in Saint Petersburg is 15 °C (59 °F) and the average low is 8 °C (47 °F).
Does it rain a lot in Saint Petersburg in September?
On average about 63 mm (2.5 in) of precipitation falls in September; it ranks 7th of the 12 months.
Is September the warmest month in Saint Petersburg?
No. The warmest month in Saint Petersburg is July, with an average high of 22 °C (72 °F). The coldest month is January, with an average low of -11 °C (11 °F).
How long is the day in Saint Petersburg in September?
In the middle of September the day in Saint Petersburg lasts about 12.7 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Saint Petersburg in September?
The average relative humidity in September is about 86%. This is a long-term average for the whole day.
How cloudy is Saint Petersburg in September?
On average about 70% 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.