Weather in St. Petersburg in September 2025
Average weather
Average temperature in St. Petersburg in September
Going from a maximum of +75°F during the day to a minimum of +41°F during the night, the temperature in September averages around +66°F.
The average maximum temperature goes down 16% by the end of the month, compared with the beginning of the month, from +72°F to +66°F.
Is St. Petersburg warm or cold in September?
St. Petersburg is typically mild in September.
Maximum temperatures go down compared to the previous month from +68°F to +59°F. The minimum temperature also goes down from +52°F to +45°F.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in St. Petersburg:
Water temperature in St. Petersburg in September
Water in St. Petersburg in September is Cold. It varies from +52°F to +61°F, with an average of +57°F. This is almost similar to the air temperature, which averages +59°F.
The water temperature in September is one of the warmest of the entire year:
Can you swim in St. Petersburg in September?
Climate in St. Petersburg in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +68°F | +59°F | +46°F | ||||
| Min. temperature | ||||||
| +36°F | +27°F | +10°F | ||||
| Max. temperature | ||||||
| +95°F | +82°F | +66°F | ||||
| Rainfall | ||||||
| 85 mm | 54 mm | 49 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 3 m/s | ||||
| Avg. water temperature | ||||||
| +64°F | +57°F | +48°F | ||||
| Humidity | ||||||
| 76% | 80% | 83% | ||||
| Air pressure | ||||||
| 1011 HPa | 1012 HPa | 1012 HPa | ||||
| Sunny days | ||||||
| 6 | 3 | 3 | ||||
| Cloudy days | ||||||
| 6 | 8 | 11 | ||||
| Rainy days | ||||||
| 17 | 18 | 15 | ||||
| Snowy days | ||||||
| 0 | 0 | 3 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +68°F in the day, the average maximum temperature lowers to +59°F. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 85 mm to 54 mm. Humidity rises from 76% to 80%. The average wind speed doesn’t change much during September, staying around 2 m/s. The days becoming less sunny, going from 6 sunny days in August to 3 in September.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in St. Petersburg is gradually increasing during September, going from 3 m/s to 3 m/s over the course of the month.
Rain
How was the weather last September in St. Petersburg?
Climate Change Over the Years
The climate in St. Petersburg in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1987 (+42°F) and the highest in 2020 (+52°F). The driest year was 1992 with only 268 mm of rainfall, and the wettest year was 2022 with 866 mm.
FAQ
Is September a good time to visit St. Petersburg?
Can you sunbathe in St. Petersburg in September?
Can you swim in St. Petersburg in September?
Is St. Petersburg rainy in September?
Is it sunny in St. Petersburg in September?
Other cities in Russia
Monthly weather in St. Petersburg
Source of the data
For this page, we’ve looked at the typical weather in St. Petersburg, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.