Suffolk County (Long Island)
September
Weather in Suffolk County, New York for September 2025
Your guide to Suffolk County weather in September - trends and predictions
In general, the average temperature in Suffolk County at the beginning of September is 23 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 19.7 °F by the end of September.
Suffolk County experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 43.8 mm.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
22°/16°
Temperatures
19 km/h
Avg max wind
72 %
Avg humidity
Suffolk County Weather September
Move between months or click on a day
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
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Moderate rain at times | 25° /21° | 1.4 mm | 6 | |
| Sept. 2 |  Partly cloudy | 24° /18° | 0 mm | 6 | |
| Sept. 3 |  Sunny | 22° /15° | 0 mm | 6 | |
| Sept. 4 | Sunny | 23° /15° | 0 mm | 6 | |
| Sept. 5 | Sunny | 22° /15° | 0 mm | 6 | |
| Sept. 6 |  Patchy rain possible | 25° /17° | 0.4 mm | 6 | |
| Sept. 7 | Moderate or heavy rain shower | 20° /16° | 5.3 mm | 5 | |
| Sept. 8 | Sunny | 21° /13° | 0 mm | 6 | |
| Sept. 9 | Partly cloudy | 22° /14° | 0 mm | 6 | |
| Sept. 10 | Sunny | 24° /16° | 0 mm | 6 | |
| Sept. 11 | Partly cloudy | 22° /15° | 0 mm | 6 | |
| Sept. 12 | Sunny | 23° /15° | 0 mm | 6 | |
| Sept. 13 | Sunny | 23° /16° | 0 mm | 6 | |
| Sept. 14 | Patchy rain possible | 26° /17° | 0.2 mm | 6 | |
| Sept. 15 | Partly cloudy | 24° /17° | 0 mm | 6 | |
| Sept. 16 | Partly cloudy | 22° /15° | 0 mm | 6 | |
| Sept. 17 |  Overcast | 22° /15° | 0 mm | 5 | |
| Sept. 18 | Overcast | 21° /18° | 0 mm | 5 | |
| Sept. 19 | Moderate or heavy rain shower | 24° /18° | 10.1 mm | 5 | |
| Sept. 20 | Patchy rain possible | 22° /18° | 0.2 mm | 5 | |
| Sept. 21 | Sunny | 23° /16° | 0 mm | 6 | |
| Sept. 22 | Partly cloudy | 20° /16° | 0 mm | 6 | |
| Sept. 23 |  Cloudy | 20° /14° | 0 mm | 5 | |
| Sept. 24 | Patchy rain possible | 20° /15° | 0.2 mm | 5 | |
| Sept. 25 | Overcast | 19° /16° | 0 mm | 4 | |
| Sept. 26 |  Heavy rain at times | 23° /17° | 15.1 mm | 5 | |
| Sept. 27 | Overcast | 20° /17° | 4.6 mm | 5 | |
| Sept. 28 | Heavy rain at times | 21° /17° | 3.5 mm | 5 | |
| Sept. 29 | Patchy rain possible | 17° /16° | 2.8 mm | 4 | |
| Sept. 30 | Overcast | 18° /15° | 0 mm | 4 | |
| Next | |||||
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.
Change Month
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 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in Suffolk County during September?
In September, Suffolk County can expect light to moderate rainfall, totaling 43.8 mm across approximately 8 days. Occasional showers are possible, and planning ahead for them could be helpful.
What are the typical wind conditions in Suffolk County during September?
The average wind speed in Suffolk County during September is 19 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 💧
UV exposure in Suffolk County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in Suffolk County
Select a location for an accurate weather forecast
More Locations Quick links
More Suffolk County weather pages
You are here
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.
Found a mistake?
We appreciate your attention to details. Tell us here.