Block Island weather in September 2025

Q: How hot is it in Block Island in September?

Daytime temperatures usually reach 22°C in Block Island in September, falling to 13°C at night.

Q: How sunny is it in Block Island in September?

There are normally 8 hours of bright sunshine each day in Block Island in September - that's 60% of daylight hours.

Q: How warm is the sea around Block Island in September?

The average sea temperature around Block Island in September is 19°C.

Q: Does it rain in Block Island in September?

There are usually 9 days with some rain in Block Island in September and the average monthly rainfall is 97mm.

Q: What is the chance of a cyclone in Block Island in September?

On average less than 1 day in September in Block Island is likely to be affected by the passage of one or more tropical storms.

Expect 72°F daytime maximum temperatures in the shade with on average 8 hours of sunshine per day in Block Island in September. Check more long-term weather averages for Block Island in September before you book your next holiday to Rhode Island in 2025/2026.

72
72°F max day temperature
8
8 hours of sunshine per day
9
9 days with some rainfall
55
55°F min night temperature
12
12 hours of daylight per day
0
No heat & humidity
3.8
3.8 inches of monthly rainfall
6
6 (High) UV index
66
66°F sea temperature

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The September weather guide for Rhode Island (Block Island) 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) | Imperial (°F)

More about the USA

How hot is it in Block Island in September?

Daytime temperatures usually reach 72°F in Block Island in September, falling to 55°F at night.

How sunny is it in Block Island in September?

There are normally 8 hours of bright sunshine each day in Block Island in September - that's 60% of daylight hours.

How warm is the sea around Block Island in September?

The average sea temperature around Block Island in September is 66°F.

Does it rain in Block Island in September?

There are usually 9 days with some rain in Block Island in September and the average monthly rainfall is 3.8 inches.

What is the chance of a hurricane in Block Island in September?

On average less than 1 day in September in Block Island is likely to be affected by the passage of one or more tropical storms.

Block Island September sunrise & sunset times

Browse the sunrise and sunset times for Block Island in September 2025. Select a month to view Block Island sunrise and sunset times for the next 12 months.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Date	Sunrise times	Sunset times
Monday, 1st September 2025	05:13	18:18
Monday, 15th September 2025	05:27	17:55
Tuesday, 30th September 2025	05:42	17:29

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Rhode Island - quick facts
Flight time^✝	11 hours
Time difference	UK -5 hours
Language(s)	English
Currency	US Dollar
Electricity	A + B plug (120V)
Driving side	Right
Visa^✝	Yes
Tourist info	Commerce RI Tourism