Mostar weather by month
Mostar runs from about 6°C in January to 28°C in August, with September the wettest month at 247 mm.
warmest month
August
28°C
coolest month
January
6°C
wettest month
September
247 mm
worst air month
December
21 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 6°C | 224 mm | 185 h | 19 |
| February | 10°C | 218 mm | 200 h | 16 |
| March | 12°C | 189 mm | 255 h | 19 |
| April | 15°C | 134 mm | 343 h | 14 |
| May | 18°C | 220 mm | 346 h | 10 |
| June | 24°C | 228 mm | 401 h | 10 |
| July | 28°C | 26 mm | 422 h | 8 |
| August | 28°C | 22 mm | 400 h | 8 |
| September | 20°C | 247 mm | 277 h | 8 |
| October | 17°C | 203 mm | 285 h | 10 |
| November | 10°C | 150 mm | 218 h | 13 |
| December | 7°C | 134 mm | 166 h | 21 |
About 3,498 hours of sun a year. Roughly 199 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 2026-05-24. Full method, licences and the list of sources we rejected are on the methodology page.