2025 Compare Climate & Weather:
Simi Valley, CA vs Irvine, CA

Highlights

On average, there are 281 sunny days per year in Irvine. Simi Valley averages 277 sunny days per year. The US average is 205 sunny days.

Irvine, California gets 12.9 inches of rain, on average, per year. Simi Valley, California gets 17.2 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

Irvine averages 0 inches of snow per year. Simi Valley averages 0 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

Irvine, California
Summer High: the July high is around 81.5 degrees
Winter Low: the January low is 46.3
Rain: averages 12.9 inches of rain a year
Snow: averages 0 inches of snow a year

Simi Valley, California
Summer High: the July high is around 92.2 degrees
Winter Low: the January low is 41.5
Rain: averages 17.2 inches of rain a year
Snow: averages 0 inches of snow a year

BestPlaces Comfort Index

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

The annual BestPlaces Comfort Index for Simi Valley is 8.6 (10=best), which means it is more comfortable than most places in California.

Today's Weather - Simi Valley, CA

53°F

Today's Weather - Irvine, CA

57°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Simi Valley / Irvine

August is the hottest month for Simi Valley with an average high temperature of 93.5°, which ranks it as warmer than most places in California. In Simi Valley, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Simi Valley are April, May and November.

August is the hottest month for Irvine with an average high temperature of 83.2°, which ranks it as cooler than most places in California. In Irvine, there are 8 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Irvine are October, June and July.

December has the coldest nighttime temperatures for Simi Valley with an average of 40.5°. This is warmer than most places in California.

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

In Simi Valley, there are 82.8 days annually when the high temperature is over 90°, which is hotter than most places in California.

In Irvine, there are 17.4 days annually when the high temperature is over 90°, which is cooler than most places in California.

In Simi Valley, there are 9.2 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in California.

In Irvine, there are 0.6 days annually when the nighttime low temperature falls below freezing, which is one of the warmest places in California.

In Simi 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 Irvine, 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 Simi Valley with 4.3 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 62% of yearly precipitation and 1% occurs in Autumn, which is the driest season. The annual rainfall of 17.2 inches in Simi Valley means that it is about average compared to other places in California.


February is the wettest month in Irvine with 3.2 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 12.9 inches in Irvine means that it is drier than most places in California.

February is the rainiest month in Simi Valley with 6.6 days of rain, and July is the driest month with only 0.2 rainy days. There are 35.0 rainy days annually in Simi Valley, which is less rainy than most places in California. The rainiest season is Spring when it rains 51% of the time and the driest is Autumn with only a 3% chance of a rainy day.

February is the rainiest month in Irvine with 6.5 days of rain, and July is the driest month with only 0.4 rainy days. There are 36.3 rainy days annually in Irvine, 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 Simi Valley, ranking it as one of the least snowy places in California.

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

Any measurable snowfall is a rare occurance in Simi Valley.

Any measurable snowfall is a rare occurance in Irvine.