September Weather in Hamden, United States

Last updated: June 24, 2025

In September, the average temperature in Hamden, United States hovers around 21°C (70°F). However, you can experience a range with minimums dipping to 6°C (43°F) and maximums soaring to 36°C (98°F). Expect about 99 mm (3.9 in) of precipitation spread over 9 days, and enjoy a comfortable average humidity of 73%.

September Temperature in Hamden

In September in Hamden, the average temperature is 21°C (70°F). The maximum can reach up to 36°C (98°F), while the minimum can drop as low as 6°C (43°F). It's an ideal time for travelers to enjoy mild weather with the possibility of warm days and cooler evenings, perfect for both outdoor adventures and relaxing strolls.

September Weather in Hamden: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Hamden, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hamden, September typically has an average temperature of 21°C (70°F), with highs reaching up to 36°C (98°F) and lows dropping to around 6°C (43°F).

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

September Precipitation in Hamden

In Hamden in September, the precipitation amount is 99 mm (3.9 in) during a span of 9 days.

September Precipitation Trends in Hamden

The chart displays monthly precipitation patterns in Hamden, 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 Hamden, September typically receives around 99 mm (3.9 inches) of precipitation spread over approximately 9 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 Hamden

In Hamden in September, humidity is 73%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace that can make outdoor activities feel sweltering, so it's essential to stay hydrated and take breaks in the shade while exploring.

September Average Humidity in Hamden

This chart illustrates the average monthly humidity levels in Hamden, 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 Hamden is approximately 73%, 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 Hamden

In Hamden 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 Hamden.

Maximum UV Index Levels in Hamden for September

The chart shows the monthly maximum UV Index (UVI) for Hamden 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 Hamden typically reaches 8, which falls under the very high exposure category.

Data source: Hamden 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 Hamden Compares to Other Months

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

This table compares monthly weather conditions in Hamden, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	1°C (34°F)	86 mm (3.4 inches)	88%	moderate
February Weather	3°C (38°F)	122 mm (4.8 inches)	88%	moderate
March Weather	7°C (45°F)	120 mm (4.7 inches)	87%	high
April Weather	12°C (54°F)	135 mm (5.3 inches)	85%	very high
May Weather	18°C (65°F)	133 mm (5.2 inches)	81%	very high
June Weather	22°C (72°F)	142 mm (5.6 inches)	82%	very high
July Weather	25°C (77°F)	112 mm (4.4 inches)	81%	very high
August Weather	24°C (75°F)	113 mm (4.4 inches)	73%	very high
September Weather	21°C (70°F)	99 mm (3.9 inches)	73%	very high
October Weather	15°C (59°F)	109 mm (4.3 inches)	78%	high
November Weather	7°C (44°F)	86 mm (3.4 inches)	89%	moderate
December Weather	4°C (39°F)	116 mm (4.6 inches)	87%	moderate