2025 Compare Climate & Weather:
San Francisco, CA vs Mackinac Island, MI

Highlights

On average, there are 159 sunny days per year in Mackinac Island. San Francisco averages 259 sunny days per year. The US average is 205 sunny days.

Mackinac Island, Michigan gets 30.2 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.

Mackinac Island averages 88.9 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

Mackinac Island, Michigan
Summer High: the July high is around 76.3 degrees
Winter Low: the January low is 9.7
Rain: averages 30.2 inches of rain a year
Snow: averages 88.9 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 Mackinac Island is 6.1 (10=best), which means it is less comfortable than most places in Michigan.

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

54°F

Today's Weather - Mackinac Island, MI

42°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: San Francisco / Mackinac Island

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.

July is the hottest month for Mackinac Island with an average high temperature of 76.3°, which ranks it as one of the coolest places in Michigan. In Mackinac Island, there are 3 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Mackinac Island are July, August and June.

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

February has the coldest nighttime temperatures for Mackinac Island with an average of 9.6°. This is colder than most places in Michigan.

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 Mackinac Island, there are 0.9 days annually when the high temperature is over 90°, which is one of the coolest places in Michigan.

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 Mackinac Island, there are 162.6 days annually when the nighttime low temperature falls below freezing, which is colder than most places in Michigan.

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 Mackinac Island, there are 18.1 days annually when the nighttime low temperature falls below zero°, which is colder than most places in Michigan.

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.


October is the wettest month in Mackinac Island with 3.5 inches of rain, and the driest month is February with 1.4 inches. The wettest season is Winter with 32% of yearly precipitation and 18% occurs in Spring, which is the driest season. The annual rainfall of 30.2 inches in Mackinac Island means that it is one of the driest places in Michigan.

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.

December is the rainiest month in Mackinac Island with 13.7 days of rain, and July is the driest month with only 8.9 rainy days. There are 131.1 rainy days annually in Mackinac Island, which is about average compared to other places in Michigan. The rainiest season is Winter when it rains 29% of the time and the driest is Autumn with only a 21% 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.

An annual snowfall of 88.9 inches in Mackinac Island means that it is snowier than most places in Michigan.

Any measurable snowfall is a rare occurance in San Francisco.

January is the snowiest month in Mackinac Island with 24.8 inches of snow, and 7 months of the year have significant snowfall.