Suffolk County (Long Island)
September
Weather in Suffolk County, New York for September 2026
Your guide to Suffolk County weather in September - trends and predictions
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So far, September 2026 in Suffolk County shows a warmer trend than usual by 2.7 °F.
Expect cooler weather in the next days in Suffolk County with the forecast suggesting a temperature of 21.1 °F, lower than the historical average.
In general, the average temperature in Suffolk County at the beginning of September is 24.3 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.9 °F by the end of September.
Suffolk County experiences moderate rainfall in September, with an average of 10 rainy days and a total precipitation of 122.9 mm.
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Temperatures
Rain 🌧️
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20
Dry days
10
Rainy days
0
Snow days
22°/17°
Temperatures
18 km/h
Avg max wind
74 %
Avg humidity
Suffolk County Weather September
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Temperatures trend during September in Suffolk County
See the weather trend as well as the moving average line
September weather in Suffolk County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Moderate rain at times | 26° /19° | 24 mm | 4 | |
| Sept. 2 |  Partly cloudy | 24° /17° | 0 mm | 5 | |
| Sept. 3 |  Sunny | 24° /16° | 8.6 mm | 4 | |
| Sept. 4 | Sunny | 24° /17° | 4 mm | 6 | |
| Sept. 5 | Sunny | 26° /17° | 11 mm | 7 | |
| Sept. 6 |  Patchy rain possible | 24° /18° | 5.3 mm | 6 | |
| Sept. 7 | Moderate or heavy rain shower | 22° /14° | 5.2 mm | 5 | |
| Sept. 8 | Sunny | 25° /13° | 0 mm | 6 | |
| Sept. 9 | Partly cloudy | 24° /15° | 0.2 mm | 4 | |
| Sept. 10 | Sunny | 25° /17° | 0.4 mm | 4 | |
| Sept. 11 | Partly cloudy | 24° /16° | 0 mm | 6 | |
| Sept. 12 | Sunny | 23° /15° | 0 mm | 6 | |
| Sept. 13 | Sunny | 23° /16° | 0 mm | 6 | |
| Sept. 14 | Sunny | 23° /19° | 0.2 mm | 6 | |
| Sept. 15 | Sunny | 20° /15° | 0 mm | 6.4 | |
| Sept. 16 |  Overcast | 22° /18° | 0 mm | 6.6 | |
| Sept. 17 |  Cloudy | 24° /21° | 0.2 mm | 6 | |
| Sept. 18 | Overcast | 23° /19° | 0.5 mm | 6 | |
| Sept. 19 | Overcast | 22° /19° | 0 mm | 6 | |
| Sept. 20 | Overcast | 25° /20° | 5.8 mm | 5 | |
| Sept. 21 | Overcast | 19° /16° | 0 mm | 5 | |
| Sept. 22 | Patchy rain possible | 18° /15° | 0.8 mm | 4 | |
| Sept. 23 | Light rain shower | 19° /15° | 19.1 mm | 4 | |
| Sept. 24 | Patchy rain possible | 17° /16° | 0.6 mm | 4 | |
| Sept. 25 | Patchy rain possible | 22° /17° | 7.6 mm | 5 | |
| Sept. 26 | Light rain shower | 22° /20° | 10.3 mm | 5 | |
| Sept. 27 | Sunny | 20° /16° | 0.1 mm | 6 | |
| Sept. 28 |  Heavy rain at times | 23° /17° | 7.6 mm | 5 | |
| Sept. 29 | Patchy rain possible | 21° /17° | 1.4 mm | 5 | |
| Sept. 30 | Overcast | 21° /16° | 0 mm | 5 | |
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Important Notice
Our weather forecast for Suffolk County in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Suffolk County forecast closer to your planned date for the most up-to-date weather information.
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Suffolk County in September - FAQ
What are the expected maximum and minimum temperatures in Suffolk County during September?
During September, expect a variety of temperatures with highs around 22° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Suffolk County during September?
Significant rainfall exceeding 122.9 mm is expected in Suffolk County during September, occurring over more than 10 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Suffolk County during September?
The average wind speed in Suffolk County during September is 18 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Suffolk County
Explore the daily rainfall trends and prepare for Suffolk Countys September weather 💧
Typically, Suffolk County has 10 rainy days in September with a total of 122.9 mm of rainfall.
UV exposure in Suffolk County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Suffolk County?Get accurate weather forecasts for Suffolk County, located at latitude 40.817 and longitude -73.066. Stay updated with localized weather information tailored for Suffolk County.
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