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San Juan weather in September 2025
Expect daytime maximum temperatures of 30°C in San Juan, Puerto Rico in September and high heat and humidity based on long-term weather averages. There are 8 hours of sunshine per day on average with 18 days with some rainfall and typically 188 mm of rainfall in the month.
- 30°C max day temperature
30 - 8 hours of sunshine per day
- 18 days with some rainfall
18 - 23°C min night temperature
23 - 12 hours of daylight per day
12 - High heat & humidity
H - 188 mm of monthly rainfall
188 - 11+ (Extreme) UV index
11 - 29°C sea temperature
29
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The September weather guide for Puerto Rico (San Juan) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.
Metric (°C / mm) | Imperial (°F / inches)
More about Puerto Rico
How hot is it in San Juan in September?
Daytime temperatures usually reach 30°C in San Juan in September with high heat and humidity, falling to 23°C at night.
How sunny is it in San Juan in September?
There are normally 8 hours of bright sunshine each day in San Juan in September - that's 64% of daylight hours.
How warm is the sea around San Juan in September?
The average sea temperature around San Juan in September is 29°C.
Does it rain in San Juan in September?
There are usually 18 days with some rain in San Juan in September and the average monthly rainfall is 188mm.
What is the chance of a hurricane in San Juan in September?
On average 1.1 days in September in San Juan are likely to be affected by the passage of one or more tropical storms.
San Juan September sunrise & sunset times
Browse the sunrise and sunset times for San Juan in September 2025. Select a month to view San Juan sunrise and sunset times for the next 12 months.
JanFebMarAprMayJunJulAugSepOctNovDec
| Date | Sunrise times | Sunset times |
|---|---|---|
| Monday, 1st September 2025 | 06:10 | 18:38 |
| Monday, 15th September 2025 | 06:12 | 18:26 |
| Tuesday, 30th September 2025 | 06:15 | 18:13 |
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