2025 Compare Climate & Weather:
Rio Vista, CA vs San Francisco, CA

Highlights

On average, there are 259 sunny days per year in San Francisco. Rio Vista averages 268 sunny days per year. The US average is 205 sunny days.

San Francisco, California gets 24.6 inches of rain, on average, per year. Rio Vista, California gets 20.3 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

San Francisco averages 0 inches of snow per year. Rio Vista averages 0 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

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

Rio Vista, California
Summer High: the July high is around 91.2 degrees
Winter Low: the January low is 38.6
Rain: averages 20.3 inches of rain a year
Snow: averages 0 inches of snow a year

BestPlaces Comfort Index

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

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

Today's Weather - Rio Vista, CA

58°F

Today's Weather - San Francisco, CA

52°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Rio Vista / San Francisco

July is the hottest month for Rio Vista with an average high temperature of 91.2°, which ranks it as about average compared to other places in California. In Rio Vista, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Rio Vista are October, May and April.

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.

December has the coldest nighttime temperatures for Rio Vista with an average of 38.5°. This is about average compared to other places in California.

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

In Rio Vista, there are 61.2 days annually when the high temperature is over 90°, which is about average compared to other 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 Rio Vista, there are 11.2 days annually when the nighttime low temperature falls below freezing, which is warmer 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 Rio Vista, 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 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.

December is the wettest month in Rio Vista with 4.0 inches of rain, and the driest month is July with 0.0 inches. The wettest season is Spring with 59% of yearly precipitation and 0% occurs in Autumn, which is the driest season. The annual rainfall of 20.3 inches in Rio Vista means that it 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.

January is the rainiest month in Rio Vista with 10.8 days of rain, and July is the driest month with only 0.0 rainy days. There are 57.9 rainy days annually in Rio Vista, which is about average compared to other places in California. The rainiest season is Spring when it rains 51% of the time and the driest is Autumn with only a 2% chance of a rainy day.

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.

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

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

Any measurable snowfall is a rare occurance in Rio Vista.

Any measurable snowfall is a rare occurance in San Francisco.