August Weather in Petaluma, United States

Last updated: June 24, 2025

In Petaluma, United States, the average temperature in August is a pleasant 18°C (65°F). It can range from a cool 10°C (51°F) to a warm 33°C (92°F), providing a nice variety for outdoor activities. With only 1 mm (0.0 in) of precipitation spread over 0 days, you can expect mostly dry conditions. The average humidity sits at a comfortable 66%, making it a great time to explore!

August Temperature in Petaluma

In August in Petaluma, the average temperature is 18°C (65°F). Maximums can reach 33°C (92°F), and minimums can be as low as 10°C (51°F). This comfortable climate makes it an ideal time for travelers to explore the beauty of Petaluma.

August Weather in Petaluma: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Petaluma, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Petaluma, August typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 10°C (51°F).

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

August Precipitation in Petaluma

In Petaluma in August, the precipitation amount is 1 mm (0.0 in) during a span of 0 days.

August Precipitation Trends in Petaluma

The chart displays monthly precipitation patterns in Petaluma, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Petaluma, August typically receives around 1 mm (0.0 inches) of precipitation spread over approximately 0 days.

Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

August Humidity in Petaluma

In Petaluma in August humidity is 66%. With an average temperature of 18°C (65°F), this humidity feels like a warm embrace, making travel comfortable yet slightly sticky, perfect for leisurely strolls but requiring light, breathable clothing to fully enjoy the experience.

August Average Humidity in Petaluma

This chart illustrates the average monthly humidity levels in Petaluma, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Petaluma is approximately 66%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Petaluma

In Petaluma in August, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Petaluma.

Maximum UV Index Levels in Petaluma for August

The chart shows the monthly maximum UV Index (UVI) for Petaluma in August, 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 August, the maximum UV index in Petaluma typically reaches 10, which falls under the very high exposure category.

Data source: Petaluma August 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 August Weather in Petaluma Compares to Other Months

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

This table compares monthly weather conditions in Petaluma, showing how August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	10°C (50°F)	131 mm (5.2 inches)	86%	moderate
February Weather	10°C (51°F)	147 mm (5.8 inches)	84%	moderate
March Weather	11°C (52°F)	93 mm (3.7 inches)	83%	high
April Weather	13°C (56°F)	45 mm (1.8 inches)	80%	very high
May Weather	15°C (60°F)	27 mm (1.0 inches)	80%	very high
June Weather	18°C (65°F)	2 mm (0.1 inches)	76%	extreme
July Weather	18°C (65°F)	1 mm (0.0 inches)	70%	extreme
August Weather	18°C (65°F)	1 mm (0.0 inches)	66%	very high
September Weather	18°C (65°F)	2 mm (0.1 inches)	68%	very high
October Weather	16°C (61°F)	38 mm (1.5 inches)	72%	high
November Weather	12°C (54°F)	59 mm (2.3 inches)	84%	moderate
December Weather	9°C (49°F)	103 mm (4.1 inches)	84%	moderate