Trieste weather by month
Trieste runs from about 6°C in January to 27°C in August, with October the wettest month at 298 mm.
warmest month
August
27°C
coolest month
January
6°C
wettest month
October
298 mm
worst air month
March
16 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 6°C | 137 mm | 190 h | 15 |
| February | 9°C | 114 mm | 156 h | 15 |
| March | 11°C | 177 mm | 227 h | 16 |
| April | 14°C | 95 mm | 301 h | 11 |
| May | 18°C | 277 mm | 336 h | 8 |
| June | 22°C | 161 mm | 381 h | 7 |
| July | 26°C | 54 mm | 417 h | 6 |
| August | 27°C | 21 mm | 394 h | 7 |
| September | 20°C | 224 mm | 259 h | 6 |
| October | 16°C | 298 mm | 205 h | 7 |
| November | 10°C | 81 mm | 203 h | 10 |
| December | 6°C | 85 mm | 176 h | 16 |
About 3,245 hours of sun a year. Roughly 173 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 2026-05-25. Full method, licences and the list of sources we rejected are on the methodology page.