Sao Luis weather by month
Sao Luis runs from about 26°C in March to 28°C in November, with March the wettest month at 590 mm.
warmest month
November
28°C
coolest month
March
26°C
wettest month
March
590 mm
worst air month
September
9 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 27°C | 229 mm | 313 h | 7 |
| February | 26°C | 410 mm | 217 h | 6 |
| March | 26°C | 590 mm | 262 h | 5 |
| April | 26°C | 487 mm | 264 h | 4 |
| May | 27°C | 194 mm | 340 h | 6 |
| June | 27°C | 88 mm | 340 h | 6 |
| July | 27°C | 30 mm | 366 h | 7 |
| August | 27°C | 28 mm | 369 h | 7 |
| September | 28°C | 19 mm | 355 h | 9 |
| October | 28°C | 28 mm | 363 h | 8 |
| November | 28°C | 40 mm | 347 h | 8 |
| December | 28°C | 90 mm | 339 h | 8 |
About 3,875 hours of sun a year. Roughly 165 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.