September Weather in Claremont, United States

Last updated: June 24, 2025

In September, the average temperature in Claremont, United States hovers around 18°C (64°F). Visitors can expect a range from a brisk 1°C (35°F) to a warm 33°C (91°F). During this month, precipitation amounts to approximately 128 mm (5.0 in), spread across about 9 days of rain. With an average humidity of 75%, the atmosphere can feel quite muggy, so pack accordingly!

September Temperature in Claremont

In September in Claremont, the average temperature is 18°C (64°F). Maximums can reach 33°C (91°F), and minimums can be as low as 1°C (35°F). Travelers should be prepared for a range of temperatures and pack accordingly for both warm days and cooler evenings.

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

The chart illustrates September temperature patterns in Claremont, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Claremont, September typically has an average temperature of 18°C (64°F), with highs reaching up to 33°C (91°F) and lows dropping to around 1°C (35°F).

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

September Precipitation in Claremont

In Claremont in September, the precipitation amount is 128 mm (5.0 in) over a span of 9 days.

September Precipitation Trends in Claremont

The chart displays monthly precipitation patterns in Claremont, 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 Claremont, September typically receives around 128 mm (5.0 inches) of precipitation spread over approximately 9 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 Claremont

In Claremont in September, humidity is 75%. With an average temperature of 18°C (64°F), this humidity feels like a warm blanket enveloping you, making your travels a bit sticky and requiring frequent breaks in the shade to stay comfortable.

September Average Humidity in Claremont

This chart illustrates the average monthly humidity levels in Claremont, 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 Claremont is approximately 75%, 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 Claremont

In Claremont 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 Claremont.

Maximum UV Index Levels in Claremont for September

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

Data source: Claremont 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 Claremont Compares to Other Months

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

This table compares monthly weather conditions in Claremont, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-9°C (17°F)	36 mm (1.4 inches)	82%	moderate
February Weather	-9°C (16°F)	45 mm (1.8 inches)	84%	moderate
March Weather	1°C (33°F)	63 mm (2.5 inches)	80%	moderate
April Weather	6°C (44°F)	94 mm (3.7 inches)	81%	very high
May Weather	15°C (59°F)	143 mm (5.6 inches)	74%	very high
June Weather	21°C (71°F)	127 mm (5.0 inches)	80%	very high
July Weather	23°C (73°F)	104 mm (4.1 inches)	80%	very high
August Weather	21°C (70°F)	121 mm (4.8 inches)	77%	very high
September Weather	18°C (64°F)	128 mm (5.0 inches)	75%	very high
October Weather	9°C (48°F)	98 mm (3.9 inches)	80%	moderate
November Weather	1°C (34°F)	43 mm (1.7 inches)	87%	moderate
December Weather	-4°C (25°F)	42 mm (1.6 inches)	83%	moderate