São Tomé weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: June – September
What is the weather like in São Tomé in September?
In September, São Tomé is warm: daytime highs average 25 °C, and even at night it stays warm at around 24 °C. The sea averages 26.1 °C – lovely and warm for swimming. Expect around 6 hours of sunshine a day. Rain falls on about 8 days, adding up to 47 mm. The air is often humid and muggy. All in all, September is an excellent month for a holiday in São Tomé.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 90 | 80 | 58 |
| Day | 25° | 25° | 26° |
| Night | 23° | 24° | 24° |
| Sea | 26° | 26° | 27° |
| Sun | 6 h | 6 h | 6 h |
| Rain days | 3 | 8 | 22 |
More details for September
- Daylight
- 12 h 7 min05:25 – 17:32
- UV index
- 15 · extremeclear sky, noon (estimate)All months
- Muggy days
- 30 daysdew point 18 °C or moreAll months
- Wind
- 24 km/haverage daily peakAll months
- Cloud cover
- 73 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Time zone
- UTC+0Africa/Sao_Tome
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %47 %
- Few rainy daysweight 30 %70 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Insect repellent
- Rain jacket or umbrella
São Tomé in September: quick answers
Is São Tomé hot in September?
Warm rather than hot: in September, daytime highs in São Tomé average 25 °C and nights cool to about 24 °C.
Can you swim in São Tomé in September?
Yes. In September the sea averages 26.1 °C – lovely and warm for swimming.
Does it rain much in São Tomé in September?
Rain falls on about 8 days, adding up to 47 mm.
São Tomé month by month
The whole year in São ToméAll destinations: São Tomé and PríncipeWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences