September Weather in Ventura, United States

Last updated: June 24, 2025

In Ventura, United States, the average temperature in September is a comfortable 18°C (65°F). However, be prepared for variability, as temperatures can dip as low as 3°C (37°F) and peak at a warm 33°C (92°F). Expect about 105 mm (4.1 in) of precipitation spread over 10 days, and enjoy a typically humid atmosphere with an average humidity of 75%.

September Temperature in Ventura

In September in Ventura, the average temperature is 18°C (65°F), with maximums that can reach 33°C (92°F) and minimums that can drop to as low as 3°C (37°F). Overall, travelers should be prepared for a range of temperatures, ensuring they pack both warm clothing for the cooler evenings and lighter attire for the hotter days.

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

The chart illustrates September temperature patterns in Ventura, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Ventura, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 3°C (37°F).

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

September Precipitation in Ventura

In Ventura in September, the precipitation amount is 105 mm (4.1 in) over the course of 10 days.

September Precipitation Trends in Ventura

The chart displays monthly precipitation patterns in Ventura, 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 Ventura, September typically receives around 105 mm (4.1 inches) of precipitation spread over approximately 10 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 Ventura

In Ventura in September, humidity is 75%. With an average temperature of 18°C (65°F), this humidity feels like a warm, enveloping blanket that can make outdoor exploration feel a bit stifling, potentially leading to discomfort during travel activities.

September Average Humidity in Ventura

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

In Ventura 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 Ventura.

Maximum UV Index Levels in Ventura for September

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

Data source: Ventura 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 Ventura Compares to Other Months

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

This table compares monthly weather conditions in Ventura, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-8°C (19°F)	36 mm (1.4 inches)	82%	moderate
February Weather	-8°C (18°F)	47 mm (1.9 inches)	84%	moderate
March Weather	1°C (35°F)	72 mm (2.9 inches)	80%	moderate
April Weather	7°C (45°F)	83 mm (3.3 inches)	81%	very high
May Weather	15°C (60°F)	159 mm (6.2 inches)	74%	very high
June Weather	22°C (72°F)	133 mm (5.2 inches)	80%	extreme
July Weather	23°C (74°F)	102 mm (4.0 inches)	80%	very high
August Weather	21°C (71°F)	121 mm (4.8 inches)	77%	very high
September Weather	18°C (65°F)	105 mm (4.1 inches)	75%	very high
October Weather	10°C (49°F)	110 mm (4.3 inches)	80%	moderate
November Weather	2°C (35°F)	47 mm (1.9 inches)	87%	moderate
December Weather	-3°C (27°F)	36 mm (1.4 inches)	83%	moderate