Rio de Janeiro weather by month
Rio de Janeiro runs from about 21°C in July to 27°C in February, with March the wettest month at 254 mm.
warmest month
February
27°C
coolest month
July
21°C
wettest month
March
254 mm
worst air month
April
25 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 27°C | 184 mm | 289 h | 18 |
| February | 27°C | 65 mm | 305 h | 19 |
| March | 26°C | 254 mm | 293 h | 20 |
| April | 25°C | 13 mm | 318 h | 25 |
| May | 25°C | 39 mm | 288 h | 19 |
| June | 23°C | 19 mm | 289 h | 20 |
| July | 21°C | 49 mm | 273 h | 23 |
| August | 22°C | 74 mm | 302 h | 22 |
| September | 24°C | 14 mm | 319 h | 17 |
| October | 23°C | 98 mm | 299 h | 16 |
| November | 24°C | 117 mm | 285 h | 20 |
| December | 25°C | 164 mm | 320 h | 17 |
About 3,580 hours of sun a year. Roughly 108 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 2026-05-22. Full method, licences and the list of sources we rejected are on the methodology page.