Frost dates in San Jose, California
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in San Jose is January 12, and the average first fall frost is December 22, from NOAA's San Jose station, 7 miles from the middle of San Jose. 1 year in 10 the last frost comes after February 14, and the first one by December 1. That leaves about 344 frost-free days. San Jose is in USDA planting zone 9b.
Weather stations around San Jose
The first row is the date most people in San Jose go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| San Jose 7 mi away, 51 ft | January 12 1 in 10 after February 14 | December 22 1 in 10 by December 1 | 344 days |
| San Jose 6 mi away, 67 ft | January 2 1 in 10 after January 23 | December 25 1 in 10 by December 4 | 357 days |
| Los Gatos 9 mi away, 365 ft | February 2 1 in 10 after March 14 | December 6 1 in 10 by November 16 | 307 days |
| Mt Hamilton 10 mi away, 4,206 ft | May 3 1 in 10 after June 5 | November 18 1 in 10 by October 22 | 199 days |
| Moffett Federal Airfield 15 mi away, 39 ft | January 6 1 in 10 after February 4 | December 23 1 in 10 by December 3 | 351 days |
Distances are from the middle of San Jose as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 95121, at the middle of the city.
Your exact ZIP code
San Jose covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of California, station by station.
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Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer