Brno weather in September
September in Brno: nice, rainy, with clean air — an excellent time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#5 of 12 months in Brno · #562 of 1413 destinations to visit in September · comfort 83/100 (tier A)
- Days
- 22°C
- Nights
- 11°C
- Wet days
- 10
- Sun
- 8.7 h
- Humidity
- 73%
- Daylight
- 13 h

Traveller notes on Brno in September
Notes from nearby Vienna (111 km away)
Brno doesn't have its own notes for September yet — these are about Vienna, close enough to share the season.
Vienna's forum calls September the calm after summer — the heat has broken, sun is still likely on most days, and the standard advice is a light jacket for the odd rainy day rather than anything heavier. Year-to-year swings are real, though: some Septembers run 25°C, others barely reach 10°C.
Other months in Brno
Forum posters describe December across the Czech Republic as capable of real cold but generally mild enough winter overall that it wouldn't stop hours of walking, with heavy snow before Christmas described as unusual though genuinely possible. Posters consistently recommend layers, a proper coat, scarf, hat and gloves, plus good walking shoes, while noting snow boots or a heavy parka usually aren't necessary. Posters specifically flag Brno's Christmas markets as starting around November 22-23rd and highlight the city's past recognition as European Capital of Christmas, with markets that stay noticeably less crowded than the bigger, more famous ones in Vienna or Prague. Posters generally rate December as a genuinely good, atmospheric time to visit Brno, cold weather included.
Forum posters describe early June as likely warm with a real chance of at least some rainy days, and June through September broadly as a stretch where rain and grey overcast skies show up more often than visitors expect - highs in the 30sC aren't unusual by height of summer, with evening storms rolling through every few days. The clear upside posters raise for June specifically: it beats the bigger July-August crowds while still bringing decent warmth. For families, Brno gets called out as especially kid-friendly, with the Villa Tugendhat, the ossuary and the Brno Zoo named as reliable options regardless of what the sky does that day.
Add your own note from Brno's card on the map.
Brno climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Brno 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 Brno'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 weatherBrno's weather peaks June–August.
Best weatherFair weatherToughest weather
What's on in Brno in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Moravian harvest and burčák
1 Sep – 20 Oct · usuallyBurčák — cloudy, half-fermented young wine that is barely wine yet — turns up in the bars and on street stalls for a few weeks in autumn, and it does not travel. Brno is the city end of the Moravian vineyards, an hour from the cellars. Source ↗
- Season
Trade fair weeks
20 Sep – 15 Oct · usuallyBook earlyThe exhibition grounds south of the centre run one of Europe's bigger engineering fairs in autumn, and hotel prices in Brno double for those weeks whatever the weather is doing. Check the fair calendar before booking. Source ↗
Nearby, and something's on
Within 300 km of Brno — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Brno?
Brno in September — FAQ
- Is September a good time to visit Brno?
- September in Brno: nice, rainy, with clean air — an excellent time to visit. It ranks #5 of 12 months for Brno on SeasonMap's comfort score (83/100).
- What is the weather like in Brno in September?
- In September, Brno averages a daily high of 21.5°C and a low of 11.1°C, with about 86.9 mm of rain over roughly 9.9 rainy days.
- What is the air quality in Brno in September?
- Brno has a mean US Air Quality Index of about 43 in September.
Within 300 km: Vienna's Film festival on Rathausplatz around 28 Jun – 5 Sep, and Prague's Mushroom season around 1 Aug – 31 Oct.