September Weather in Brighton, United States

Last updated: June 24, 2025

In Brighton, United States, the average temperature in September is a pleasant 20°C (69°F). However, temperatures can range from a chilly 0°C (33°F) to a scorching 38°C (101°F). Expect a light precipitation of 18 mm (0.7 in) over about 4 days, accompanied by an average humidity of 79%. Stay prepared for a mix of conditions!

September Temperature in Brighton

In September in Brighton, the average temperature is 20°C (69°F). Maximum can reach 38°C (101°F), and minimum can be as low as 0°C (33°F). This makes Brighton an ideal destination for travelers seeking warm weather along with the possibility of cooler evenings.

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

The chart illustrates September temperature patterns in Brighton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Brighton, September typically has an average temperature of 20°C (69°F), with highs reaching up to 38°C (101°F) and lows dropping to around 0°C (33°F).

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

September Precipitation in Brighton

In Brighton in September, the total precipitation amount is 18 mm (0.7 in) spread over a duration of 4 days.

September Precipitation Trends in Brighton

The chart displays monthly precipitation patterns in Brighton, 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 Brighton, September typically receives around 18 mm (0.7 inches) of precipitation spread over approximately 4 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Brighton

In Brighton in September humidity is 79%. With an average temperature of 20°C (69°F), this humidity feels like a warm, steamy embrace, making travel slightly uncomfortable as the air feels heavy and sticky, often leaving you yearning for a cool breeze or air conditioning to escape the dampness.

September Average Humidity in Brighton

This chart illustrates the average monthly humidity levels in Brighton, 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 Brighton is approximately 79%, 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 Brighton

In Brighton in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Brighton.

Maximum UV Index Levels in Brighton for September

The chart shows the monthly maximum UV Index (UVI) for Brighton 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 Brighton typically reaches 9, which falls under the very high exposure category.

Data source: Brighton 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 Brighton Compares to Other Months

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

This table compares monthly weather conditions in Brighton, 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 (31°F)	14 mm (0.5 inches)	74%	moderate
February Weather	-1°C (31°F)	14 mm (0.6 inches)	75%	moderate
March Weather	6°C (43°F)	46 mm (1.8 inches)	66%	high
April Weather	10°C (50°F)	36 mm (1.4 inches)	62%	very high
May Weather	15°C (59°F)	84 mm (3.3 inches)	74%	extreme
June Weather	22°C (72°F)	31 mm (1.2 inches)	76%	extreme
July Weather	25°C (77°F)	30 mm (1.2 inches)	75%	extreme
August Weather	24°C (75°F)	28 mm (1.1 inches)	80%	extreme
September Weather	20°C (69°F)	18 mm (0.7 inches)	79%	very high
October Weather	10°C (51°F)	22 mm (0.9 inches)	77%	high
November Weather	5°C (42°F)	14 mm (0.5 inches)	74%	moderate
December Weather	1°C (34°F)	8 mm (0.3 inches)	80%	moderate