September Weather in Danbury, United States

Last updated: June 24, 2025

The average temperature in Danbury, United States during September is a warm 27°C (81°F). While daytime highs can reach up to 34°C (94°F), evenings cool down to a mild 15°C (58°F). Be prepared for 204 mm (8.0 in) of precipitation spread over 17 days, and enjoy the lush atmosphere brought by an average humidity of 73%.

September Temperature in Danbury

In September in Danbury, the average temperature is 27°C (81°F). The maximum can reach 34°C (94°F), while the minimum can drop to as low as 15°C (58°F). This variability makes it a great time for travelers to enjoy both warm and cool activities.

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

The chart illustrates September temperature patterns in Danbury, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Danbury, September typically has an average temperature of 27°C (81°F), with highs reaching up to 34°C (94°F) and lows dropping to around 15°C (58°F).

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

September Precipitation in Danbury

In Danbury in September, the precipitation amount is 204 mm (8.0 in) occurring over 17 days.

September Precipitation Trends in Danbury

The chart displays monthly precipitation patterns in Danbury, 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 Danbury, September typically receives around 204 mm (8.0 inches) of precipitation spread over approximately 17 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 Danbury

In Danbury in September, humidity is 73%. With an average temperature of 27°C (81°F), this humidity feels like a warm blanket enveloping you, making outdoor activities feel sticky and heavy, while also requiring frequent hydration breaks to stay comfortable during your travels.

September Average Humidity in Danbury

This chart illustrates the average monthly humidity levels in Danbury, 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 Danbury 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 Danbury

In Danbury in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Danbury.

Maximum UV Index Levels in Danbury for September

The chart shows the monthly maximum UV Index (UVI) for Danbury 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 Danbury typically reaches 11, which falls under the extreme exposure category.

Data source: Danbury 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 Danbury Compares to Other Months

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

This table compares monthly weather conditions in Danbury, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	13°C (56°F)	76 mm (3.0 inches)	78%	moderate
February Weather	15°C (59°F)	73 mm (2.9 inches)	81%	very high
March Weather	19°C (66°F)	64 mm (2.5 inches)	76%	very high
April Weather	21°C (71°F)	83 mm (3.3 inches)	79%	extreme
May Weather	25°C (78°F)	165 mm (6.5 inches)	79%	extreme
June Weather	28°C (82°F)	158 mm (6.2 inches)	74%	extreme
July Weather	28°C (84°F)	151 mm (5.9 inches)	71%	extreme
August Weather	29°C (84°F)	183 mm (7.2 inches)	68%	extreme
September Weather	27°C (81°F)	204 mm (8.0 inches)	73%	extreme
October Weather	23°C (74°F)	105 mm (4.1 inches)	75%	very high
November Weather	18°C (64°F)	74 mm (2.9 inches)	78%	high
December Weather	15°C (60°F)	95 mm (3.8 inches)	84%	moderate