2025 Compare Climate & Weather:
Petaluma, CA vs Seattle, WA

Highlights

On average, there are 152 sunny days per year in Seattle. Petaluma averages 260 sunny days per year. The US average is 205 sunny days.

Seattle, Washington gets 38 inches of rain, on average, per year. Petaluma, California gets 29.8 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Seattle averages 4.6 inches of snow per year. Petaluma averages 0 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Seattle, Washington
Summer High: the July high is around 75.8 degrees
Winter Low: the January low is 37
Rain: averages 38 inches of rain a year
Snow: averages 4.6 inches of snow a year

Petaluma, California
Summer High: the July high is around 83.7 degrees
Winter Low: the January low is 38.7
Rain: averages 29.8 inches of rain a year
Snow: averages 0 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Seattle is 7.5 (10=best), which means it is one of the most pleasant places in Washington.

The annual BestPlaces Comfort Index for Petaluma is 8.4 (10=best), which means it is more comfortable than most places in California.

Today's Weather - Petaluma, CA

50°F

Today's Weather - Seattle, WA

47°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Petaluma / Seattle

August is the hottest month for Petaluma with an average high temperature of 83.7°, which ranks it as cooler than most places in California. In Petaluma, there are 6 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Petaluma are October, June and May.

August is the hottest month for Seattle with an average high temperature of 76.3°, which ranks it as cooler than most places in Washington. In Seattle, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Seattle are August, July and September.

December has the coldest nighttime temperatures for Petaluma with an average of 38.3°. This is about average compared to other places in California.

December has the coldest nighttime temperatures for Seattle with an average of 35.9°. This is one of the warmest places in Washington.

In Petaluma, there are 28.1 days annually when the high temperature is over 90°, which is cooler than most places in California.

In Seattle, there are 1.7 days annually when the high temperature is over 90°, which is cooler than most places in Washington.

In Petaluma, there are 16.7 days annually when the nighttime low temperature falls below freezing, which is about average compared to other places in California.

In Seattle, there are 24.0 days annually when the nighttime low temperature falls below freezing, which is one of the warmest places in Washington.

In Petaluma, there are 0.0 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in California.

In Seattle, there are 0.0 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Washington.

December is the wettest month in Petaluma with 5.7 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 57% of yearly precipitation and 1% occurs in Autumn, which is the driest season. The annual rainfall of 29.8 inches in Petaluma means that it is wetter than most places in California.


November is the wettest month in Seattle with 6.2 inches of rain, and the driest month is July with 0.8 inches. The wettest season is Spring with 39% of yearly precipitation and 9% occurs in Autumn, which is the driest season. The annual rainfall of 38.0 inches in Seattle means that it is about average compared to other places in Washington.

January is the rainiest month in Petaluma with 12.5 days of rain, and July is the driest month with only 0.2 rainy days. There are 74.8 rainy days annually in Petaluma, which is rainier than most places in California. The rainiest season is Spring when it rains 49% of the time and the driest is Autumn with only a 2% chance of a rainy day.

November is the rainiest month in Seattle with 18.7 days of rain, and August is the driest month with only 5.3 rainy days. There are 155.3 rainy days annually in Seattle, which is about average compared to other places in Washington. The rainiest season is Spring when it rains 33% of the time and the driest is Autumn with only a 13% chance of a rainy day.

There is rarely any recorded snowfall in Petaluma, ranking it as one of the least snowy places in California.

An annual snowfall of 4.6 inches in Seattle means that it is about average compared to other places in Washington.

Any measurable snowfall is a rare occurance in Petaluma.

December is the snowiest month in Seattle with 2.1 inches of snow, and 4 months of the year have significant snowfall.