September Weather in Brilliant, United States

Last updated: June 24, 2025

In September, the average temperature in Brilliant, United States hovers around 24°C (76°F), offering a pleasant climate for outdoor activities. However, temperatures can vary significantly, with lows reaching 11°C (51°F) and peaking at 37°C (98°F). Expect about 98 mm (3.9 in) of precipitation over 8 days, contributing to an average humidity of 74% that keeps the air feeling refreshing yet warm.

September Temperature in Brilliant

In September in Brilliant, the average temperature is 24°C (76°F). The maximum can reach 37°C (98°F) and the minimum can be as low as 11°C (51°F). It's a great time to visit for those who enjoy warm weather with a pleasant range of temperatures.

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

The chart illustrates September temperature patterns in Brilliant, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Brilliant, September typically has an average temperature of 24°C (76°F), with highs reaching up to 37°C (98°F) and lows dropping to around 11°C (51°F).

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

September Precipitation in Brilliant

In Brilliant in September, the total precipitation amount is 98 mm (3.9 in), occurring over 8 days.

September Precipitation Trends in Brilliant

The chart displays monthly precipitation patterns in Brilliant, 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 Brilliant, September typically receives around 98 mm (3.9 inches) of precipitation spread over approximately 8 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 Brilliant

In Brilliant in September, humidity is 74%. With an average temperature of 24°C (76°F), this humidity feels like a warm, heavy blanket wrapping around you, making travel a bit sticky and requiring plenty of hydration as you explore.

September Average Humidity in Brilliant

This chart illustrates the average monthly humidity levels in Brilliant, 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 Brilliant is approximately 74%, 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 Brilliant

In Brilliant 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 Brilliant.

Maximum UV Index Levels in Brilliant for September

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

Data source: Brilliant 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 Brilliant Compares to Other Months

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

This table compares monthly weather conditions in Brilliant, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (45°F)	121 mm (4.8 inches)	85%	moderate
February Weather	10°C (50°F)	195 mm (7.7 inches)	84%	high
March Weather	14°C (57°F)	175 mm (6.9 inches)	82%	very high
April Weather	17°C (62°F)	171 mm (6.7 inches)	82%	very high
May Weather	22°C (72°F)	122 mm (4.8 inches)	82%	extreme
June Weather	25°C (77°F)	144 mm (5.7 inches)	79%	extreme
July Weather	27°C (80°F)	112 mm (4.4 inches)	82%	extreme
August Weather	26°C (80°F)	126 mm (5.0 inches)	77%	extreme
September Weather	24°C (76°F)	98 mm (3.9 inches)	74%	very high
October Weather	19°C (66°F)	111 mm (4.4 inches)	73%	high
November Weather	11°C (52°F)	73 mm (2.9 inches)	85%	moderate
December Weather	9°C (49°F)	155 mm (6.1 inches)	88%	moderate