Last spring frost
Feb 26
Frost Dates for Sea Ranch, CA
First fall frost
Dec 27
Growing season
310 days
Hardiness zone
9b
In an average year around Sea Ranch, CA, the last spring frost (32°F) is about Feb 26 and the first fall frost is about Dec 27, giving roughly a 310-day growing season. To be safe most years, wait until Dec 27 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.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 19 | Apr 17 | Mar 11 |
| Freeze (32°F) | May 1 | Feb 26 | Dec 27 |
| Hard (28°F) | Apr 28 | Jan 29 | Dec 9 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 19 | May 10 | May 1 | Apr 25 | Apr 17 | Apr 11 | Apr 4 | Mar 26 | Mar 11 |
| 32°F | May 1 | Apr 14 | Mar 25 | Mar 10 | Feb 26 | Feb 12 | Jan 30 | Jan 11 | Dec 27 |
| 28°F | Apr 28 | Apr 6 | Feb 25 | Feb 14 | Jan 29 | Jan 16 | Jan 2 | Dec 23 | Dec 9 |
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.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 20 | Nov 25 | Dec 24 |
| Freeze (32°F) | Dec 1 | Dec 27 | Feb 27 |
| Hard (28°F) | Dec 5 | Jan 16 | Apr 18 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 20 | Nov 1 | Nov 10 | Nov 18 | Nov 25 | Dec 1 | Dec 6 | Dec 14 | Dec 24 |
| 32°F | Dec 1 | Dec 6 | Dec 15 | Dec 21 | Dec 27 | Jan 3 | Jan 10 | Feb 2 | Feb 27 |
| 28°F | Dec 5 | Dec 15 | Dec 27 | Jan 3 | Jan 16 | Feb 1 | Feb 16 | Feb 27 | Apr 18 |
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
@endif These dates are computed from the nearest official weather station with long-term records: Ft Ross, Ca, about 14.2 miles away@if(!empty($station['elevation_ft'])), at 112 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
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 Sea Ranch, CA?
On average, the last spring frost (32°F) around Sea Ranch, CA is about Feb 26. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 27.
When is the first frost in the fall?
The first fall frost around Sea Ranch, CA typically arrives about Dec 27. 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 Feb 26 on average, or Dec 27 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 310 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 95412 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026