Montauk, Long Island 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
Fair
Best time to visit: July – August
What is the weather like in Montauk, Long Island in September?
In September, Montauk, Long Island is warm: daytime highs average 21 °C, and nights cool down to about 18 °C. The sea averages 20.1 °C – refreshing for a swim. The sun shines for around 7 hours a day. Rain falls on about 9 days, adding up to 101 mm. It is often windy, with gusts of around 30 km/h. All in all, September is a so-so month for a holiday in Montauk, Long Island.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 73 | 48 | 21 |
| Day | 24° | 21° | 16° |
| Night | 21° | 18° | 13° |
| Sea | 21° | 20° | 17° |
| Sun | 8 h | 7 h | 6 h |
| Rain days | 8 | 9 | 10 |
More details for September
- Daylight
- 12 h 32 min06:27 – 18:59
- UV index
- 6 · highclear sky, noon (estimate)All months
- Muggy days
- 9 daysdew point 18 °C or moreAll months
- Wind
- 30 km/haverage daily peakAll months
- Cloud cover
- 50 %on averageAll months
- Hot days
- 0 days30 °C or moreAll months
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC−4America/New_York
How the score comes together
- Temperatureweight 35 %33 %
- Seaweight 25 %44 %
- Sunshineweight 20 %60 %
- Few rainy daysweight 20 %65 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in September
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Rain jacket or umbrella
- Windproof jacket
Montauk, Long Island in September: quick answers
Is Montauk, Long Island hot in September?
Warm rather than hot: in September, daytime highs in Montauk, Long Island average 21 °C and nights cool to about 18 °C.
Can you swim in Montauk, Long Island in September?
Yes. In September the sea averages 20.1 °C – refreshing for a swim.
Does it rain much in Montauk, Long Island in September?
Rain falls on about 9 days, adding up to 101 mm.
Montauk, Long Island month by month
The whole year in Montauk, Long IslandAll destinations: USAWhere 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