expatwhy.

Leuven weather by month

Leuven runs from about 3°C in January to 20°C in August, with May the wettest month at 120 mm.

warmest month

August

20°C

coolest month

January

3°C

wettest month

May

120 mm

worst air month

March

17 µg/m³

The whole year, month by month.

Monthly climate normals for Leuven
MonthAvg tempRainSunPM2.5
January3°C63 mm130 h13
February8°C112 mm105 h9
March9°C88 mm194 h17
April11°C94 mm268 h11
May15°C120 mm284 h9
June16°C78 mm313 h8
July18°C100 mm333 h7
August20°C72 mm318 h7
September16°C85 mm256 h6
October13°C67 mm177 h9
November7°C64 mm102 h9
December5°C69 mm80 h12

About 2,560 hours of sun a year. Roughly 101 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.

where these numbers come from

  • · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
  • · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.

Last reviewed 2026-05-27. Full method, licences and the list of sources we rejected are on the methodology page.