expatwhy.

Brno weather by month

Brno runs from about 0°C in January to 23°C in August, with September the wettest month at 207 mm.

warmest month

August

23°C

coolest month

January

0°C

wettest month

September

207 mm

worst air month

December

28 µg/m³

The whole year, month by month.

Monthly climate normals for Brno
MonthAvg tempRainSunPM2.5
January0°C54 mm164 h24
February7°C45 mm137 h20
March8°C52 mm245 h19
April12°C31 mm284 h11
May16°C94 mm349 h8
June20°C88 mm369 h7
July23°C24 mm394 h5
August23°C38 mm375 h7
September17°C207 mm253 h6
October11°C42 mm201 h7
November4°C18 mm155 h22
December1°C33 mm96 h28

About 3,022 hours of sun a year. Roughly 72 rainy days a year.

These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.