Weather in Saint Petersburg for the month
The full September calendar: model forecast through September 19, then the long-term climate normal.
🔮 What September will be like
📅 September calendar2-week forecast →
🏆 September records in Saint PetersburgArchive & climate →
🌅 September astronomy
🌊 Water in September
📒 Weather diary in Saint Petersburg
Ready-made observation table for September: past days are already filled in with weather-station data — for school and beyond. Open the diary →
✉️ Weather forecast by email
Get the forecast for this city by email — every day at 17:00 Moscow time.
FAQ about weather in Saint Petersburg ❓
What will the weather be like in September in Saint Petersburg?
The forecast part of September is near normal: +15°…+22° by day, 1 of 11 days rainy. The second half is shown from the climate normal: on average +16° by day and +10° at night.
When are the best days of September?
The forecast points to 15 September: +17°, precipitation 10%. Models don’t see beyond two weeks — check back, the page updates daily.
How accurate is a monthly forecast?
Honestly: models are reliable up to ~14 days. So through September 19 we show the model forecast, and beyond that — each day’s climate normal from long-term observations (ERA5). It is a statistical expectation, not a guarantee.
Weather in Saint Petersburg — in detail
Weather forecast in Saint Petersburg for the month: from +11° to +22° day and night. Warmest day — Wednesday, September 9 (up to +22°). Coolest — Tuesday, September 15 (+11°). Precipitation chance up to 93%. Trend: it cools toward the end. See also the forecast for 2 weeks and the weather archive.
To quickly check the weather in Saint Petersburg anytime, add the city to favorites — and get a daily forecast by email at 17:00 (Moscow time). Note: the forecast may be refined as new data arrives. Data: OpenWeather, Open-Meteo, met.no.