Rosario weather by month
Rosario runs from about 9°C in July to 25°C in February, with March the wettest month at 201 mm.
warmest month
February
25°C
coolest month
July
9°C
wettest month
March
201 mm
worst air month
July
11 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 25°C | 136 mm | 393 h | 7 |
| February | 25°C | 108 mm | 321 h | 6 |
| March | 24°C | 201 mm | 327 h | 7 |
| April | 18°C | 175 mm | 201 h | 7 |
| May | 12°C | 9 mm | 256 h | 7 |
| June | 14°C | 12 mm | 225 h | 9 |
| July | 9°C | 5 mm | 251 h | 11 |
| August | 12°C | 67 mm | 212 h | 9 |
| September | 17°C | 5 mm | 328 h | 6 |
| October | 20°C | 120 mm | 307 h | 7 |
| November | 23°C | 49 mm | 350 h | 9 |
| December | 23°C | 53 mm | 404 h | 9 |
About 3,575 hours of sun a year. Roughly 96 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 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.