Harman US

Frost Dates for San Jose, CA

Last spring frost
Jan 12
First fall frost
Dec 22
Growing season
347 days
Hardiness zone
9b

In an average year around San Jose, CA, the last spring frost (32°F) is about Jan 12 and the first fall frost is about Dec 22, giving roughly a 347-day growing season. To be safe most years, wait until Dec 20 before setting out tender plants.

Last spring frost

Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.

Last spring frost - San Jose, CA
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Mar 9 Feb 12 Jan 11
Freeze (32°F) Feb 14 Jan 12 Dec 20
Hard (28°F) Jan 17 Dec 31 Dec 10
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Mar 9 Mar 1 Feb 25 Feb 18 Feb 12 Feb 6 Jan 31 Jan 24 Jan 11
32°F Feb 14 Feb 2 Jan 26 Jan 18 Jan 12 Jan 6 Dec 31 Dec 28 Dec 20
28°F Jan 17 Jan 10 Jan 5 Jan 2 Dec 31 Dec 29 Dec 27 Dec 21 Dec 10

First fall frost

Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.

First fall frost - San Jose, CA
Frost intensity Early (10%) Average (50%) Late (90%)
Light (36°F) Nov 17 Dec 3 Dec 31
Freeze (32°F) Dec 1 Dec 22 Jan 20
Hard (28°F) Dec 6 Dec 28 Jan 14
Show full probability table (all thresholds & percentiles)
°F 10% 20% 30% 40% 50% 60% 70% 80% 90%
36°F Nov 17 Nov 22 Nov 27 Nov 30 Dec 3 Dec 7 Dec 11 Dec 16 Dec 31
32°F Dec 1 Dec 6 Dec 12 Dec 17 Dec 22 Dec 27 Jan 1 Jan 6 Jan 20
28°F Dec 6 Dec 14 Dec 21 Dec 25 Dec 28 Dec 31 Jan 2 Jan 7 Jan 14

Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.

Where this data comes from

These dates are computed from the nearest official weather station with long-term records: San Jose, Ca, about 5.6 miles away@if(!empty($station['elevation_ft'])), at 51 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.

@endif
How we calculate these dates

Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.

Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.

Frequently asked questions

When is the last frost in San Jose, CA?

On average, the last spring frost (32°F) around San Jose, CA is about Jan 12. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 20.

When is the first frost in the fall?

The first fall frost around San Jose, CA typically arrives about Dec 22. Count back by a crop's days to maturity to find the latest date you can plant it.

When can I plant tomatoes and other tender crops?

Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Jan 12 on average, or Dec 20 to be safe most years.

How long is the growing season here?

The frost-free growing season (between the last spring and first fall 32°F frost) is about 347 days in a typical year.

Are these dates a forecast for this year?

No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.

Local weather for 95129 Planting calendar → California frost dates →

Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026