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Frost Dates in California
First and last frost dates across California, computed from 176 NOAA weather stations (1991–2020 climate normals). Your exact date depends on your city and microclimate — use the ZIP lookup on the main tool for a station-specific answer.
Last spring frost
Feb 26
statewide median · range Dec 29–Jun 14
First fall frost
Nov 28
statewide median · range Sep 10–Jan 14
Growing season
272 days
median · range 91–365
Stations used
176
NOAA 1991–2020 normals
Frost dates by city
Median dates from the nearest NOAA station to each city. The "cautious" date is the 10% spring value — planting after it means only a ~10% chance of a later frost.
| City | Nearest station | Last spring frost | First fall frost | Growing season | Safe transplant |
|---|---|---|---|---|---|
| Los Angeles | Pasadena · 9 mi | Jan 8 (cautious: Feb 17) | Jan 7 | 365 days | Jan 22 |
| San Francisco | San Francisco Intl Ap · 11 mi | Dec 29 (cautious: Jan 13) | Dec 26 | 365 days | Jan 12 |
| San Diego | El Cajon · 14 mi | Jan 6 (cautious: Feb 7) | Dec 21 | 350 days | Jan 20 |
| Sacramento | Sacramento 5 Ese · 4 mi | Jan 12 (cautious: Feb 8) | Dec 16 | 341 days | Jan 26 |
| Fresno | Fresno Yosemite Intl · 5 mi | Jan 14 (cautious: Feb 11) | Dec 14 | 337 days | Jan 28 |
How frost varies across California
Spring frost timing spans about 167 days across the state. San Francisco in western California typically sees its last spring frost around December 29, while Jess Valley in northern California doesn't clear frost until about June 14. Within any city, low spots and valleys run colder than the station average; areas near buildings and pavement run warmer.
When to plant in California
As a rule of thumb, cool-season crops (lettuce, peas, spinach) can go in 2–4 weeks before your last spring frost; warm-season transplants (tomatoes, peppers) should wait about 2 weeks after it — around March 12 for the statewide median. Check your city's row above rather than the statewide median: a 167-day statewide spread makes the city-level date the one that matters.
These are climate normals (what's typical), not forecasts. For the current year, watch the 10-day forecast around your planting date.
How this is computed
Statewide medians are the median of the 176 NOAA stations' median frost dates — half the stations run earlier, half later. City rows use the nearest station with 30-year freeze records. Dates are 32°F freeze probabilities from NOAA NCEI 1991–2020 U.S. Climate Normals; nothing is estimated or interpolated.
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Frequently asked questions
When is the last frost date in California?
The statewide median last spring frost is February 26, but it ranges from December 29 to June 14 depending on where in the state you are. Use your city's row in the table above, or the ZIP lookup on the main tool, for a station-specific date.
When can I plant tomatoes outside in California?
Warm-season transplants like tomatoes should wait about two weeks after your last spring frost — around March 12 for the statewide median. Your city may differ by weeks; check the "safe transplant" column in the city table.
How long is the growing season in California?
The median growing season across 176 NOAA stations is 272 days, ranging from 91 to 365 days by location.
Why do frost dates vary so much within California?
Frost timing follows latitude, elevation, and local terrain. Across California, last spring frost dates span about 167 days — from around December 29 near San Francisco to June 14 near Jess Valley. Microclimates (low spots, valleys, urban heat) shift dates further at the garden level.
Where does this data come from?
All frost dates are computed from the NOAA National Centers for Environmental Information 1991–2020 U.S. Climate Normals freeze data (public domain), using each station's 32°F freeze probability statistics. No dates are estimated or interpolated.