São Luís weather in September
September is one of the best months to visit São Luís: highs of 32°C (89°F) and about 23 mm (0.9 in) of rain on average. Nights average 25°C (76°F) and cloud cover 25% (NASA POWER, 2001–2025 averages). The sea averages 29°C (84°F). It is the 3rd driest month of the year and the warmest. Compared with August, it is warmer and about as wet; October brings highs of 31°C (89°F) and 15 mm (0.6 in) of rain.
Is September a good time to visit São Luís?
best month Weather score 89/100.
Yes. September is one of the best months for weather in São Luís.
Does it rain a lot in São Luís in September?
No, it is usually dry: about 23 mm (0.9 in) falls in an average September. It is the 3rd driest month of the year.
How warm is São Luís in September?
Days average 32°C (89°F) and nights 25°C (76°F).
São Luís weather by month
| Month | High | Low | Rain | Cloud | Sea | Weather |
|---|---|---|---|---|---|---|
| January | 30°C (85°F) | 25°C (76°F) | 191 mm | 73% | 30°C (85°F) | fair |
| February | 29°C (83°F) | 25°C (76°F) | 247 mm | 81% | 30°C (86°F) | least pleasant |
| March | 28°C (83°F) | 25°C (76°F) | 322 mm | 82% | 30°C (86°F) | least pleasant |
| April | 28°C (82°F) | 25°C (77°F) | 357 mm | 82% | 30°C (86°F) | least pleasant |
| May | 28°C (83°F) | 25°C (77°F) | 238 mm | 67% | 31°C (87°F) | least pleasant |
| June | 29°C (84°F) | 25°C (76°F) | 149 mm | 50% | 30°C (87°F) | fair |
| July | 29°C (84°F) | 24°C (76°F) | 88 mm | 38% | 30°C (86°F) | best |
| August | 31°C (87°F) | 24°C (76°F) | 23 mm | 26% | 30°C (85°F) | best |
| September | 32°C (89°F) | 25°C (76°F) | 23 mm | 25% | 29°C (84°F) | best |
| October | 31°C (89°F) | 25°C (77°F) | 15 mm | 34% | 29°C (84°F) | best |
| November | 31°C (88°F) | 25°C (78°F) | 17 mm | 46% | 29°C (84°F) | best |
| December | 31°C (87°F) | 25°C (78°F) | 47 mm | 58% | 29°C (84°F) | best |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis), sea temperature from Open-Meteo Marine. Page updated . How we rate months