Can you swim at Fire Island in September? — 20.0°C water
Yes — comfortable for most swimmers
Average sea · September
20.0°C
Live water now
…
Recommended wetsuit
Shorty 2mm
warm
Yes. With a 20.0°C average in September, most swimmers find Fire Island comfortable after the first 10–20 seconds of acclimatisation.
Monthly averages set expectations, but the specific beach today depends on wind, swell and recent weather. Check the live value at the top of this page or open the Fire Island live page for full conditions.
Best months to swim
July · August
Frequently asked questions
What is the average sea temperature at Fire Island in September?
Fire Island averages 20.0°C in September, based on long-run climatology for the Atlantic Ocean.
Is the sea warm enough to swim at Fire Island in September?
Yes, most swimmers find 20.0°C comfortable for unrestricted swimming.
Do I need a wetsuit at Fire Island in September?
Most swimmers don't need a wetsuit; a rash vest helps for longer sessions.
