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

Poznań🇵🇱 Poland · Central Europe · City85
  1. 41Jan
  2. 52Feb
  3. 65Mar
  4. 77Apr
  5. 83May
  6. 92Jun
  7. 87Jul
  8. 90Aug
  9. 85Sep
  10. 69Oct
  11. 57Nov
  12. 45Dec

#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
Poznań, Poland
Photo: Jakub Zerdzicki · Pexels

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.
Tripadvisor community · September · 1 month ago · about Wrocław · Read more on Tripadvisor ↗

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.
Tripadvisor community · January · 1 month ago · Read more on Tripadvisor ↗
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.
Tripadvisor community · July · 1 month ago · Read more on Tripadvisor ↗

Add your own note from Poznań's card on the map.

Poznań climate normals — September

Daytime high22°C / 71°F😎 nice
Nighttime low10°C / 50°F
Feels like (high)20°C / 68°F
Rainfall46 mm / 1.8 in🌦 some rain
Rainy days8 days
Humidity72%💧 humid
Dew point10°C / 50°F
Sunshine8.4 h/day
Daylight12.6 h
Wind17 km/h / 11 mph
Air quality (US AQI)45🍃 good

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)

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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.

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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 early

    The 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 ↗

What's on around the world in September →

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?

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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.