September Weather in Port Jefferson Station, United States

Last updated: June 24, 2025

In September, the average temperature in Port Jefferson Station, United States hovers around 21°C (70°F). Expect a comfortable range with a minimum of 11°C (52°F) and a peak reaching 30°C (87°F). However, be prepared for some rain, as 94 mm (3.7 in) of precipitation is likely over 10 days. With an average humidity of 68%, it’s a great time to enjoy the warmth while staying hydrated!

September Temperature in Port Jefferson Station

In September, in Port Jefferson Station, the average temperature is 21°C (70°F). The maximum can reach 30°C (87°F) and the minimum can be as low as 11°C (52°F). This pleasant climate makes Port Jefferson Station an ideal destination for travelers seeking comfortable weather and outdoor activities.

September Weather in Port Jefferson Station: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Port Jefferson Station, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Port Jefferson Station, September typically has an average temperature of 21°C (70°F), with highs reaching up to 30°C (87°F) and lows dropping to around 11°C (52°F).

Data source: Temperature data for Port Jefferson Station generated using information from the Copernicus Climate Change Service.

September Precipitation in Port Jefferson Station

In Port Jefferson Station in September, the precipitation amount is 94 mm (3.7 in) over a duration of 10 days.

September Precipitation Trends in Port Jefferson Station

The chart displays monthly precipitation patterns in Port Jefferson Station, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Port Jefferson Station, September typically receives around 94 mm (3.7 inches) of precipitation spread over approximately 10 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Port Jefferson Station

In Port Jefferson Station in September humidity is 68%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace, making the air feel slightly heavy and sticky, which can be quite exhausting for travelers.

September Average Humidity in Port Jefferson Station

This chart illustrates the average monthly humidity levels in Port Jefferson Station, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Port Jefferson Station is approximately 68%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Port Jefferson Station

In Port Jefferson Station in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Port Jefferson Station.

Maximum UV Index Levels in Port Jefferson Station for September

The chart shows the monthly maximum UV Index (UVI) for Port Jefferson Station in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Port Jefferson Station typically reaches 8, which falls under the very high exposure category.

Data source: Port Jefferson Station September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How September Weather in Port Jefferson Station Compares to Other Months

Weather in Port Jefferson Station varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Port Jefferson Station, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Port Jefferson Station, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (35°F)	80 mm (3.1 inches)	84%	moderate
February Weather	2°C (36°F)	112 mm (4.4 inches)	82%	moderate
March Weather	4°C (40°F)	104 mm (4.1 inches)	81%	high
April Weather	9°C (49°F)	132 mm (5.2 inches)	78%	very high
May Weather	14°C (58°F)	119 mm (4.7 inches)	69%	very high
June Weather	20°C (68°F)	87 mm (3.4 inches)	69%	very high
July Weather	24°C (76°F)	131 mm (5.2 inches)	62%	very high
August Weather	24°C (75°F)	103 mm (4.0 inches)	65%	very high
September Weather	21°C (70°F)	94 mm (3.7 inches)	68%	very high
October Weather	16°C (61°F)	143 mm (5.6 inches)	74%	high
November Weather	9°C (49°F)	103 mm (4.0 inches)	82%	moderate
December Weather	5°C (40°F)	140 mm (5.5 inches)	80%	low