2025 Compare Climate & Weather:
Arlington, MA vs San Mateo, CA

Highlights

On average, there are 265 sunny days per year in San Mateo. Arlington averages 200 sunny days per year. The US average is 205 sunny days.

San Mateo, California gets 24.4 inches of rain, on average, per year. Arlington, Massachusetts gets 48.2 inches of rain, on average, per year. The US average is 38.1 inches of rain per year.

San Mateo averages 0 inches of snow per year. Arlington averages 52.6 inches of snow per year. The US average is 27.8 inches of snow per year.

Weather Highlights

San Mateo, California
Summer High: the July high is around 74.1 degrees
Winter Low: the January low is 42.2
Rain: averages 24.4 inches of rain a year
Snow: averages 0 inches of snow a year

Arlington, Massachusetts
Summer High: the July high is around 82.4 degrees
Winter Low: the January low is 18.3
Rain: averages 48.2 inches of rain a year
Snow: averages 52.6 inches of snow a year

BestPlaces Comfort Index

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

The annual BestPlaces Comfort Index for Arlington is 6.9 (10=best), which means it is about average compared to other places in Massachusetts.

Today's Weather - Arlington, MA

43°F

Today's Weather - San Mateo, CA

53°F

Average Monthly High / Low (°F)

Hot, Freezing, Rainy, Snowy Days: Arlington / San Mateo

July is the hottest month for Arlington with an average high temperature of 82.4°, which ranks it as warmer than most places in Massachusetts. In Arlington, there are 4 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for Arlington are June, August and July.

August is the hottest month for San Mateo with an average high temperature of 74.5°, which ranks it as one of the coolest places in California. In San Mateo, there are 5 comfortable months with high temperatures in the range of 70-85°. The most pleasant months of the year for San Mateo are August, September and July.

January has the coldest nighttime temperatures for Arlington with an average of 18.3°. This is about average compared to other places in Massachusetts.

January has the coldest nighttime temperatures for San Mateo with an average of 42.2°. This is warmer than most places in California.

In Arlington, there are 10.1 days annually when the high temperature is over 90°, which is hotter than most places in Massachusetts.

In San Mateo, there are 9.4 days annually when the high temperature is over 90°, which is cooler than most places in California.

In Arlington, there are 121.5 days annually when the nighttime low temperature falls below freezing, which is about average compared to other places in Massachusetts.

In San Mateo, there are 4.6 days annually when the nighttime low temperature falls below freezing, which is warmer than most places in California.

In Arlington, there are 2.4 days annually when the nighttime low temperature falls below zero°, which is about average compared to other places in Massachusetts.

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

March is the wettest month in Arlington with 4.7 inches of rain, and the driest month is February with 3.5 inches. The wettest season is Summer with 26% of yearly precipitation and 24% occurs in Spring, which is the driest season. The annual rainfall of 48.2 inches in Arlington means that it is about average compared to other places in Massachusetts.


January is the wettest month in San Mateo with 4.8 inches of rain, and the driest month is July with 0.1 inches. The wettest season is Spring with 57% of yearly precipitation and 2% occurs in Autumn, which is the driest season. The annual rainfall of 24.4 inches in San Mateo means that it is wetter than most places in California.

May is the rainiest month in Arlington with 13.0 days of rain, and September is the driest month with only 9.3 rainy days. There are 134.3 rainy days annually in Arlington, which is one of the rainiest places in Massachusetts. The rainiest season is Summer when it rains 28% of the time and the driest is Winter with only a 23% chance of a rainy day.

January is the rainiest month in San Mateo with 11.6 days of rain, and July is the driest month with only 1.7 rainy days. There are 76.9 rainy days annually in San Mateo, which is rainier than most places in California. The rainiest season is Spring when it rains 44% of the time and the driest is Autumn with only a 7% chance of a rainy day.

An annual snowfall of 52.6 inches in Arlington means that it is snowier than most places in Massachusetts.

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

January is the snowiest month in Arlington with 15.5 inches of snow, and 6 months of the year have significant snowfall.

Any measurable snowfall is a rare occurance in San Mateo.