2025 Compare Climate & Weather:
Grass Valley, CA vs Santa Rosa, CA

Highlights

On average, there are 256 sunny days per year in Santa Rosa. Grass Valley averages 243 sunny days per year. The US average is 205 sunny days.

Santa Rosa, California gets 38.2 inches of rain, on average, per year. Grass Valley, California gets 55 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Santa Rosa averages 0 inches of snow per year. Grass Valley averages 11.3 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Santa Rosa, California
Summer High: the July high is around 83.8 degrees
Winter Low: the January low is 38
Rain: averages 38.2 inches of rain a year
Snow: averages 0 inches of snow a year

Grass Valley, California
Summer High: the July high is around 87.2 degrees
Winter Low: the January low is 34.2
Rain: averages 55 inches of rain a year
Snow: averages 11.3 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Santa Rosa is 8.3 (10=best), which means it is more comfortable than most places in California.

The annual BestPlaces Comfort Index for Grass Valley is 7.9 (10=best), which means it is less comfortable than most places in California.

Today's Weather - Grass Valley, CA

83°F

Today's Weather - Santa Rosa, CA

84°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Grass Valley / Santa Rosa

July is the hottest month for Grass Valley with an average high temperature of 87.2°, which ranks it as about average compared to other places in California. In Grass Valley, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Grass Valley are June, September and May.

August is the hottest month for Santa Rosa with an average high temperature of 84.1°, which ranks it as cooler than most places in California. In Santa Rosa, there are 7 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Santa Rosa are October, May and June.

December has the coldest nighttime temperatures for Grass Valley with an average of 34.0°. This is colder than most places in California.

December has the coldest nighttime temperatures for Santa Rosa with an average of 37.5°. This is about average compared to other places in California.

In Grass Valley, there are 28.3 days annually when the high temperature is over 90°, which is cooler than most places in California.

In Santa Rosa, there are 31.5 days annually when the high temperature is over 90°, which is cooler than most places in California.

In Grass Valley, there are 45.7 days annually when the nighttime low temperature falls below freezing, which is colder than most places in California.

In Santa Rosa, there are 22.4 days annually when the nighttime low temperature falls below freezing, which is colder than most places in California.

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

December is the wettest month in Grass Valley with 10.4 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 53% of yearly precipitation and 2% occurs in Autumn, which is the driest season. The annual rainfall of 55.0 inches in Grass Valley means that it is one of the wettest places in California.


December is the wettest month in Santa Rosa with 7.4 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 38.2 inches in Santa Rosa means that it is wetter than most places in California.

January is the rainiest month in Grass Valley with 12.7 days of rain, and July is the driest month with only 0.3 rainy days. There are 83.8 rainy days annually in Grass Valley, which is one of the rainiest places in California. The rainiest season is Spring when it rains 44% of the time and the driest is Autumn with only a 4% chance of a rainy day.

January is the rainiest month in Santa Rosa with 12.8 days of rain, and July is the driest month with only 0.2 rainy days. There are 75.7 rainy days annually in Santa Rosa, 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.

An annual snowfall of 11.3 inches in Grass Valley means that it is snowier than most places in California.

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

February is the snowiest month in Grass Valley with 3.7 inches of snow, and 6 months of the year have significant snowfall.

Any measurable snowfall is a rare occurance in Santa Rosa.