September Weather in Campbell, United States

Last updated: June 24, 2025

In September, the average temperature in Campbell, United States hovers around 19°C (67°F), with a comfortable average humidity of 55%. Expect minimum temperatures to dip to 7°C (45°F) and soar to a maximum of 41°C (106°F) on warmer days. Precipitation is quite low, with just 3 mm (0.1 in) recorded over 0 days, making it a great time to enjoy the outdoors!

September Temperature in Campbell

In September in Campbell, the average temperature is 19°C (67°F). Maximum temperatures can reach 41°C (106°F), while the minimum can drop as low as 7°C (45°F). Be prepared for a wide range of temperatures and pack accordingly for your travels.

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

The chart illustrates September temperature patterns in Campbell, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Campbell, September typically has an average temperature of 19°C (67°F), with highs reaching up to 41°C (106°F) and lows dropping to around 7°C (45°F).

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

September Precipitation in Campbell

In Campbell in September, the precipitation amount is 3 mm (0.1 in) during a total of 0 days.

September Precipitation Trends in Campbell

The chart displays monthly precipitation patterns in Campbell, 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 Campbell, September typically receives around 3 mm (0.1 inches) of precipitation spread over approximately 0 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 Campbell

In Campbell in September, humidity is 55%. With an average temperature of 19°C (67°F), this humidity feels like a refreshing embrace, perfect for leisurely strolls and outdoor adventures.

September Average Humidity in Campbell

This chart illustrates the average monthly humidity levels in Campbell, 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 Campbell is approximately 55%, 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 Campbell

In Campbell 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 Campbell.

Maximum UV Index Levels in Campbell for September

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

Data source: Campbell 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 Campbell Compares to Other Months

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

This table compares monthly weather conditions in Campbell, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	10°C (51°F)	145 mm (5.7 inches)	82%	moderate
February Weather	11°C (52°F)	133 mm (5.2 inches)	84%	moderate
March Weather	11°C (53°F)	114 mm (4.5 inches)	82%	very high
April Weather	13°C (56°F)	37 mm (1.4 inches)	78%	very high
May Weather	15°C (59°F)	24 mm (0.9 inches)	71%	extreme
June Weather	18°C (64°F)	1 mm (0.0 inches)	64%	extreme
July Weather	19°C (66°F)	0 mm (0.0 inches)	58%	extreme
August Weather	19°C (67°F)	0 mm (0.0 inches)	54%	very high
September Weather	19°C (67°F)	3 mm (0.1 inches)	55%	very high
October Weather	17°C (63°F)	25 mm (1.0 inches)	62%	high
November Weather	13°C (56°F)	56 mm (2.2 inches)	78%	moderate
December Weather	10°C (50°F)	116 mm (4.6 inches)	80%	moderate