São Tomé weather in September
September in São Tomé: hot, a little rain, with clean air — an excellent time to visit.
#4 of 12 months in São Tomé · #253 of 604 destinations to visit in September · comfort 83/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
São Tomé climate normals — September
| Daytime high | 27°C / 80°F | 🥵 hot |
|---|---|---|
| Nighttime low | 25°C / 77°F | |
| Feels like (high) | 30°C / 86°F | |
| Rainfall | 43 mm / 1.7 in | 🌦 some rain |
| Rainy days | 6 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 22°C / 72°F | |
| Sunshine | 9.8 h/day | |
| Daylight | 12.1 h | |
| Wind | 24 km/h / 15 mph | |
| Air quality (US AQI) | 38 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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São Tomé in September — FAQ
- Is September a good time to visit São Tomé?
- September in São Tomé: hot, a little rain, with clean air — an excellent time to visit. It ranks #4 of 12 months for São Tomé on SeasonMap's comfort score (83/100).
- What is the weather like in São Tomé in September?
- In September, São Tomé averages a daily high of 26.8°C and a low of 25.1°C, with about 43.4 mm of rain over roughly 5.8 rainy days.
- What is the air quality in São Tomé in September?
- São Tomé has a mean US Air Quality Index of about 38 in September.