Last spring frost
May 4
Frost Dates for Forbestown, CA
First fall frost
Oct 30
Growing season
174 days
Hardiness zone
9a
In an average year around Forbestown, CA, the last spring frost (32°F) is about May 4 and the first fall frost is about Oct 30, giving roughly a 174-day growing season. To be safe most years, wait until Apr 18 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) | Jun 14 | May 29 | May 6 |
| Freeze (32°F) | May 31 | May 4 | Apr 18 |
| Hard (28°F) | May 8 | Apr 15 | Mar 23 |
| Severe (24°F) | Apr 14 | Mar 15 | Feb 8 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 14 | Jun 8 | Jun 4 | Jun 1 | May 29 | May 25 | May 19 | May 13 | May 6 |
| 32°F | May 31 | May 23 | May 14 | May 9 | May 4 | Apr 30 | Apr 27 | Apr 22 | Apr 18 |
| 28°F | May 8 | Apr 28 | Apr 22 | Apr 18 | Apr 15 | Apr 11 | Apr 5 | Apr 1 | Mar 23 |
| 24°F | Apr 14 | Apr 7 | Mar 31 | Mar 25 | Mar 15 | Mar 7 | Mar 1 | Feb 20 | Feb 8 |
| 20°F | Mar 9 | Feb 28 | Feb 19 | Feb 11 | Jan 30 | Jan 18 | Jan 8 | Jan 1 | Dec 20 |
| 16°F | Feb 26 | Feb 18 | Feb 6 | Jan 21 | Jan 10 | Jan 3 | Dec 31 | Dec 22 | Dec 14 |
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) | Sep 22 | Oct 9 | Oct 28 |
| Freeze (32°F) | Oct 7 | Oct 30 | Nov 14 |
| Hard (28°F) | Oct 28 | Nov 16 | Dec 3 |
| Severe (24°F) | Nov 17 | Dec 6 | Dec 28 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 22 | Sep 28 | Oct 1 | Oct 6 | Oct 9 | Oct 13 | Oct 16 | Oct 21 | Oct 28 |
| 32°F | Oct 7 | Oct 15 | Oct 19 | Oct 24 | Oct 30 | Nov 1 | Nov 5 | Nov 8 | Nov 14 |
| 28°F | Oct 28 | Nov 4 | Nov 9 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 27 | Dec 3 |
| 24°F | Nov 17 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 9 | Dec 14 | Dec 19 | Dec 28 |
| 20°F | Dec 1 | Dec 7 | Dec 13 | Dec 19 | Dec 27 | Dec 31 | Jan 8 | Jan 22 | Feb 14 |
| 16°F | Dec 8 | Dec 16 | Dec 21 | Dec 29 | Jan 1 | Jan 7 | Jan 21 | Feb 6 | Feb 24 |
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: Strawberry Valley, Ca, about 9.4 miles away@if(!empty($station['elevation_ft'])), at 3,808 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 Forbestown, CA?
On average, the last spring frost (32°F) around Forbestown, CA is about May 4. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 18.
When is the first frost in the fall?
The first fall frost around Forbestown, CA typically arrives about Oct 30. 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 May 4 on average, or Apr 18 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 174 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 95941 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026