2025 Compare Climate & Weather:
Napa, CA vs Costa Mesa, CA

Highlights

On average, there are 274 sunny days per year in Costa Mesa. Napa averages 260 sunny days per year. The US average is 205 sunny days.

Costa Mesa, California gets 12 inches of rain, on average, per year. Napa, California gets 27.3 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. Napa 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

Napa, California
Summer High: the July high is around 82.4 degrees
Winter Low: the January low is 37.7
Rain: averages 27.3 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 Napa is 8.4 (10=best), which means it is more comfortable than most places in California.

Today's Weather - Napa, CA

84°F

Today's Weather - Costa Mesa, CA

78°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Napa / Costa Mesa

August is the hottest month for Napa with an average high temperature of 83.0°, which ranks it as cooler than most places in California. In Napa, there are 7 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Napa are October, May and June.

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.

December has the coldest nighttime temperatures for Napa with an average of 37.4°. This is about average compared to other 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 Napa, there are 24.6 days annually when the high temperature is over 90°, which is cooler than most 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 Napa, there are 21.3 days annually when the nighttime low temperature falls below freezing, which is colder than most 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 Napa, 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.

February is the wettest month in Napa with 5.4 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 58% of yearly precipitation and 1% occurs in Autumn, which is the driest season. The annual rainfall of 27.3 inches in Napa 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 Napa with 12.0 days of rain, and July is the driest month with only 0.1 rainy days. There are 68.6 rainy days annually in Napa, which is rainier 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 2% 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 Napa, 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 Napa.

Any measurable snowfall is a rare occurance in Costa Mesa.