September Weather in Oakland, United States

Last updated: June 24, 2025

In Oakland, United States, the average temperature in September is a pleasant 20°C (69°F), with minimums dipping to 5°C (41°F) and maximums soaring to 36°C (97°F). Expect 78 mm (3.1 in) of precipitation spread over 9 days, and enjoy the humid atmosphere with an average humidity level of 75%.

September Temperature in Oakland

In September in Oakland, the average temperature is 20°C (69°F). Maximum temperatures can reach 36°C (97°F), while minimums can drop as low as 5°C (41°F). This makes Oakland a versatile destination for travelers, offering warmth during the day and cooler evenings to enjoy outdoor activities.

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

The chart illustrates September temperature patterns in Oakland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Oakland, September typically has an average temperature of 20°C (69°F), with highs reaching up to 36°C (97°F) and lows dropping to around 5°C (41°F).

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

September Precipitation in Oakland

In Oakland in September, the precipitation amount is 78 mm (3.1 in) over the course of 9 days.

September Precipitation Trends in Oakland

The chart displays monthly precipitation patterns in Oakland, 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 Oakland, September typically receives around 78 mm (3.1 inches) of precipitation spread over approximately 9 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 Oakland

In Oakland in September, humidity is 75%. With an average temperature of 20°C (69°F), this humidity feels like a warm, enveloping blanket, making travel a bit muggy and requiring frequent hydration breaks to stay comfortable while exploring.

September Average Humidity in Oakland

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

In Oakland 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 Oakland.

Maximum UV Index Levels in Oakland for September

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

Data source: Oakland 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 Oakland Compares to Other Months

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

This table compares monthly weather conditions in Oakland, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-4°C (24°F)	30 mm (1.2 inches)	76%	moderate
February Weather	-4°C (24°F)	29 mm (1.2 inches)	80%	moderate
March Weather	4°C (40°F)	92 mm (3.6 inches)	73%	high
April Weather	9°C (49°F)	65 mm (2.6 inches)	74%	very high
May Weather	16°C (62°F)	152 mm (6.0 inches)	78%	very high
June Weather	24°C (75°F)	116 mm (4.6 inches)	82%	very high
July Weather	25°C (77°F)	71 mm (2.8 inches)	83%	very high
August Weather	23°C (74°F)	113 mm (4.4 inches)	80%	very high
September Weather	20°C (69°F)	78 mm (3.1 inches)	75%	very high
October Weather	11°C (52°F)	95 mm (3.7 inches)	75%	high
November Weather	4°C (39°F)	29 mm (1.1 inches)	82%	moderate
December Weather	-1°C (30°F)	44 mm (1.7 inches)	83%	low