Poznań weather in September
September in Poznań: nice, a little rain, with clean air — an excellent time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#4 of 12 months in Poznań · #502 of 1413 destinations to visit in September · comfort 85/100 (tier A)
- Days
- 22°C
- Nights
- 10°C
- Wet days
- 8
- Sun
- 8.4 h
- Humidity
- 72%
- Daylight
- 13 h

Traveller notes on Poznań in September
Notes from nearby Wrocław (145 km away)
Poznań doesn't have its own notes for September yet — these are about Wrocław, close enough to share the season.
Wroclaw forum regulars rate September highly, especially the first half: one trip report from early September describes “excellent weather with perfect temperatures” and the city “looking stunning in sunshine,” with a specific day hitting 25°C. The broader read holds through much of the month — “perfectly good...until mid-October, with little rain, dry air, and pleasant nights.” One timing note worth knowing: the Japanese Garden and the university's Botanical Garden, two of the city's best-regarded attractions, are open only April through October, so September beats the shoulder months either side of that window. Our record: 20.2°C days, 11.9°C nights, 8.6 rain days and 8.6 hours of sun — mild and reasonably dry, consistent with the “perfectly good” read, if a touch cooler than the specific 25°C day one visitor caught.
Other months in Poznań
Forum posters describe January in Poland, Poznań included, as likely snowy and cold, though posters are direct this isn't guaranteed - one recent year turned out surprisingly mild, with temperatures well above 0C across much of the country. Posters generally describe the range of possible January days as genuinely wide: it could be +10C with heavy rain, -10C with heavy snowfall, sunny, or foggy, all within the same month. Posters consistently recommend checking a reliable Polish weather site closer to travel dates rather than relying on generic seasonal averages, given how variable a specific January in Poznań can turn out. Posters generally recommend preparing for cold, potentially snowy conditions while accepting that the exact experience varies significantly year to year.
Forum posters put July generally around 20-25C and pleasant, though occasional heat waves can push things warmer, and posters flag July as one of Poland's rainier months compared to May or September - with the caveat that many buildings lack air conditioning, so a heat wave can feel worse than the number suggests. For the visit itself, Poznan's Old Market Square with the town hall is called an absolute must, complete with a daily noon show of two mechanical goats butting heads on the tower - and the Old Town is described as lively and safe well into the evening. Visitors timing a trip for late June will just miss the Malta International Theatre Festival, though summer concerts pick up the slack in July.
Add your own note from Poznań's card on the map.
Poznań climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Poznań in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Shoulder seasonschool holidays in 3 of the markets that fill it, an ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Poznań's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherPoznań's weather peaks June–August.
Best weatherFair weatherToughest weather
What's on in Poznań in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Trade fair weeks
1 Jan – 31 DecBook earlyThe fairgrounds sit next to the main station and have done since 1921, so a big fair week fills every central hotel and doubles the rate with no relation to the season. Check the calendar before booking. Source ↗
Nearby, and something's on
Within 300 km of Poznań — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Poznań?
Poznań in September — FAQ
- Is September a good time to visit Poznań?
- September in Poznań: nice, a little rain, with clean air — an excellent time to visit. It ranks #4 of 12 months for Poznań on SeasonMap's comfort score (85/100).
- What is the weather like in Poznań in September?
- In September, Poznań averages a daily high of 21.6°C and a low of 10°C, with about 45.9 mm of rain over roughly 8.3 rainy days.
- What is the air quality in Poznań in September?
- Poznań has a mean US Air Quality Index of about 45 in September.
Within 300 km: Warsaw's Chopin concerts in Lazienki on 5 Jul – 27 Sep, and Berlin's Berlin Marathon on 27 Sep.