Hillsborough, CA Weather & Climate Normals
Hillsborough's real weather, in one number
Hillsborough, CA scores 80/100 on this site's reading of NOAA's own 30-year normals: very mild year-round. Many months fall in a comfortable temperature range with limited snow or seasonal extremes. 9 of the year's 12 months average between 55 and 75°F, the range this site counts as mild.
Hillsborough's hottest and coldest months
Hillsborough's hottest month is Sep, averaging 65°F; its coldest is Jan, averaging 51°F, a 14.1°F swing across the year, one of the smaller gaps in this dataset.
Rain and snow in Hillsborough
Over a typical year, Hillsborough sees about 19.64in of precipitation a year across roughly 65 days with measurable rain or snow. That station has no snowfall reading, so none is shown rather than assumed.
Where Hillsborough ranks
Hillsborough ranks 129 of 4876 US cities in this dataset for comfort score, and 129 of 429 within CA. About 11,171 people live there.
If you need tomorrow's forecast, not the 30-year average
Everything above is a 30-year average from SAN FRANCISCO INTL AP, CA US, 4.3 miles from Hillsborough, not a prediction for any specific day.
More on how this is worked out
Why some cities show no snow or rain figure · What a 30-year climate normal actually is