San Mateo, CA Weather & Climate Normals
What a normal year in San Mateo actually looks like
On the 30-year record NOAA keeps for San Mateo, CA, the comfort score comes out to 80/100, very mild year-round: Many months fall in a comfortable temperature range with limited snow or seasonal extremes. Only 9 months a year land in the 55–75°F range this site treats as mild.
How much San Mateo's weather actually swings
Average temperatures in San Mateo run from 51°F in Jan up to 65°F in Sep, a 14.1°F seasonal swing, one of the smaller gaps in this dataset.
How wet San Mateo actually gets
San Mateo averages 19.64in of precipitation a year across roughly 65 days with measurable rain or snow; the nearest NOAA station does not record snowfall, so no snow figure is shown rather than guessed.
San Mateo against the rest of the country
Out of 4876 cities scored here, San Mateo comes in at 113; within CA alone it ranks 113 of 429. Population is about 103,006.
Checking the actual forecast
These figures come from SAN FRANCISCO INTL AP, CA US, the NOAA station 5.1 miles from San Mateo, averaged over 30 years, not tomorrow's forecast.
More on how this is worked out
Why some cities show no snow or rain figure · What a 30-year climate normal actually is