Last spring frost
May 12
Frost Dates for Hornbrook, CA
First fall frost
Oct 8
Growing season
148 days
Hardiness zone
8a
In an average year around Hornbrook, CA, the last spring frost (32°F) is about May 12 and the first fall frost is about Oct 8, giving roughly a 148-day growing season. To be safe most years, wait until Apr 26 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 17 | May 31 | May 15 |
| Freeze (32°F) | Jun 1 | May 12 | Apr 26 |
| Hard (28°F) | May 13 | Apr 25 | Apr 6 |
| Severe (24°F) | Apr 25 | Apr 5 | Mar 12 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 17 | Jun 11 | Jun 6 | Jun 3 | May 31 | May 28 | May 24 | May 20 | May 15 |
| 32°F | Jun 1 | May 26 | May 21 | May 16 | May 12 | May 9 | May 5 | Apr 30 | Apr 26 |
| 28°F | May 13 | May 7 | May 2 | Apr 28 | Apr 25 | Apr 21 | Apr 16 | Apr 12 | Apr 6 |
| 24°F | Apr 25 | Apr 18 | Apr 13 | Apr 9 | Apr 5 | Mar 31 | Mar 27 | Mar 21 | Mar 12 |
| 20°F | Apr 6 | Apr 1 | Mar 23 | Mar 14 | Mar 9 | Mar 4 | Feb 27 | Feb 19 | Feb 8 |
| 16°F | Mar 9 | Mar 1 | Feb 22 | Feb 17 | Feb 11 | Feb 4 | Jan 26 | Jan 12 | Dec 28 |
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 11 | Sep 26 | Oct 9 |
| Freeze (32°F) | Sep 24 | Oct 8 | Oct 22 |
| Hard (28°F) | Oct 6 | Oct 22 | Nov 5 |
| Severe (24°F) | Oct 19 | Nov 3 | Nov 23 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 11 | Sep 16 | Sep 20 | Sep 23 | Sep 26 | Sep 29 | Oct 1 | Oct 4 | Oct 9 |
| 32°F | Sep 24 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 22 |
| 28°F | Oct 6 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 24 | Oct 28 | Nov 1 | Nov 5 |
| 24°F | Oct 19 | Oct 24 | Oct 28 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 16 | Nov 23 |
| 20°F | Oct 30 | Nov 4 | Nov 10 | Nov 14 | Nov 19 | Nov 24 | Nov 29 | Dec 3 | Dec 11 |
| 16°F | Nov 10 | Nov 19 | Nov 26 | Dec 1 | Dec 5 | Dec 10 | Dec 18 | Dec 27 | Jan 8 |
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: Montague Siskiyou Co Ap, Ca, about 14.8 miles away@if(!empty($station['elevation_ft'])), at 2,635 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 Hornbrook, CA?
On average, the last spring frost (32°F) around Hornbrook, CA is about May 12. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 26.
When is the first frost in the fall?
The first fall frost around Hornbrook, CA typically arrives about Oct 8. 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 12 on average, or Apr 26 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 148 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 96044 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026