San Mateo, CA Frost Dates
The last spring frost in San Mateo usually comes around December 29 and the first fall frost around December 26.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | December 29 | December 26 |
| Hard freeze, 28°F | Rare | Rare |
Growing season: about 365 days.
Frequently asked questions
When is the last frost in San Mateo, CA?
The median date of the last spring frost (32°F) is December 29. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past December 29 lowers the risk for tender plants.
When is the first frost in San Mateo?
The median date of the first fall frost (32°F) is December 26.
How long is the growing season in San Mateo?
About 365 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00023234. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.