2025 Compare Climate & Weather:
San Francisco, CA vs Costa Mesa, CA

Highlights

On average, there are 274 sunny days per year in Costa Mesa. San Francisco averages 259 sunny days per year. The US average is 205 sunny days.

Costa Mesa, California gets 12 inches of rain, on average, per year. San Francisco, California gets 24.6 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Costa Mesa averages 0 inches of snow per year. San Francisco averages 0 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Costa Mesa, California
Summer High: the July high is around 77.7 degrees
Winter Low: the January low is 47.8
Rain: averages 12 inches of rain a year
Snow: averages 0 inches of snow a year

San Francisco, California
Summer High: the July high is around 67.2 degrees
Winter Low: the January low is 45.5
Rain: averages 24.6 inches of rain a year
Snow: averages 0 inches of snow a year

BestPlaces Comfort Index

The annual BestPlaces Comfort Index for Costa Mesa is 9.3 (10=best), which means it is one of the most pleasant places in California.

The annual BestPlaces Comfort Index for San Francisco is 8.5 (10=best), which means it is more comfortable than most places in California.

Today's Weather - San Francisco, CA

51°F

Today's Weather - Costa Mesa, CA

57°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: San Francisco / Costa Mesa

September is the hottest month for San Francisco with an average high temperature of 69.9°, which ranks it as one of the coolest places in California. In San Francisco, there are 0 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for San Francisco are September, October and August.

August is the hottest month for Costa Mesa with an average high temperature of 79.4°, which ranks it as cooler than most places in California. In Costa Mesa, there are 7 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Costa Mesa are July, September and August.

January has the coldest nighttime temperatures for San Francisco with an average of 45.5°. This is one of the warmest places in California.

December has the coldest nighttime temperatures for Costa Mesa with an average of 47.1°. This is one of the warmest places in California.

In San Francisco, there are 1.9 days annually when the high temperature is over 90°, which is one of the coolest places in California.

In Costa Mesa, there are 10.4 days annually when the high temperature is over 90°, which is cooler than most places in California.

In San Francisco, there are 0.3 days annually when the nighttime low temperature falls below freezing, which is one of the warmest places in California.

In Costa Mesa, there are 0.1 days annually when the nighttime low temperature falls below freezing, which is one of the warmest places in California.

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

January is the wettest month in San Francisco with 4.8 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 24.6 inches in San Francisco means that it is wetter than most places in California.


February is the wettest month in Costa Mesa with 2.8 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 60% of yearly precipitation and 1% occurs in Autumn, which is the driest season. The annual rainfall of 12.0 inches in Costa Mesa means that it is drier than most places in California.

December is the rainiest month in San Francisco with 11.7 days of rain, and July is the driest month with only 0.6 rainy days. There are 72.3 rainy days annually in San Francisco, which is rainier than most places in California. The rainiest season is Spring when it rains 48% of the time and the driest is Autumn with only a 4% chance of a rainy day.

February is the rainiest month in Costa Mesa with 6.6 days of rain, and July is the driest month with only 0.4 rainy days. There are 36.4 rainy days annually in Costa Mesa, which is less rainy than most places in California. The rainiest season is Spring when it rains 50% of the time and the driest is Autumn with only a 4% chance of a rainy day.

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

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

Any measurable snowfall is a rare occurance in San Francisco.

Any measurable snowfall is a rare occurance in Costa Mesa.