Weather in St Thomas Island in September 2025
Average weather
Average temperature in St Thomas Island in September
The temperature in September is +84°F on average, with a range between a maximum of +84°F during the day and a minimum of +81°F at night.
The average maximum temperature goes up 0% by the end of the month, compared with the beginning of the month, from +84°F to +84°F.
Is St Thomas Island warm or cold in September?
St Thomas Island is typically warm in September.
Maximum temperatures go up compared to the previous month from +82°F to +82°F. The minimum temperature also goes up from +79°F to +79°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
September is one of the warmest months in St Thomas Island, here is the comparison with other months:
Climate in St Thomas Island in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +82°F | +82°F | +82°F | ||||
| Min. temperature | ||||||
| +73°F | +75°F | +73°F | ||||
| Max. temperature | ||||||
| +91°F | +90°F | +90°F | ||||
| Rainfall | ||||||
| 113 mm | 153 mm | 151 mm | ||||
| Wind | ||||||
| 5 m/s | 4 m/s | 4 m/s | ||||
| Humidity | ||||||
| 82% | 82% | 82% | ||||
| Air pressure | ||||||
| 1014 HPa | 1013 HPa | 1012 HPa | ||||
| Sunny days | ||||||
| 2 | 2 | 3 | ||||
| Cloudy days | ||||||
| 2 | 2 | 2 | ||||
| Rainy days | ||||||
| 27 | 26 | 27 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. The temperature levels stay the same in the area of +82°F for average maximum temperature during the day. Prepare for more rain. Average rainfall goes from 113 mm to 153 mm. Humidity levels don’t change as the month goes on, averaging around 82%. Winds are calmer in comparison to August, going down from 5 m/s to 4 m/s on average. The amount of sunny days stay about the same, averaging 2 sunny days during the month.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 4 m/s getting up to 7 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in St Thomas Island is gradually increasing during September, going from 4 m/s to 5 m/s over the course of the month.
Rain
How was the weather last September in St Thomas Island?
Climate Change Over the Years
The climate in St Thomas Island in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1985 (+78°F) and the highest in 2020 (+84°F). The driest year was 2000 with only 546 mm of rainfall, and the wettest year was 2005 with 1557 mm.
FAQ
Is September a good time to visit St Thomas Island?
Can you sunbathe in St Thomas Island in September?
Is St Thomas Island rainy in September?
Is it sunny in St Thomas Island in September?
Monthly weather in St Thomas Island
Source of the data
For this page, we’ve looked at the typical weather in St Thomas Island, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.