Last spring frost
Jan 31
Frost Dates for Allendale, CA
First fall frost
Dec 11
Growing season
318 days
Hardiness zone
9b
In an average year around Allendale, CA, the last spring frost (32°F) is about Jan 31 and the first fall frost is about Dec 11, giving roughly a 318-day growing season. To be safe most years, wait until Dec 30 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) | Apr 7 | Mar 8 | Feb 4 |
| Freeze (32°F) | Mar 11 | Jan 31 | Dec 30 |
| Hard (28°F) | Jan 31 | Jan 6 | Dec 16 |
| Severe (24°F) | Jan 16 | Dec 30 | Dec 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 7 | Mar 29 | Mar 21 | Mar 14 | Mar 8 | Mar 2 | Feb 26 | Feb 19 | Feb 4 |
| 32°F | Mar 11 | Feb 25 | Feb 15 | Feb 6 | Jan 31 | Jan 24 | Jan 17 | Jan 7 | Dec 30 |
| 28°F | Jan 31 | Jan 23 | Jan 17 | Jan 11 | Jan 6 | Jan 2 | Dec 30 | Dec 23 | Dec 16 |
| 24°F | Jan 16 | Jan 9 | Jan 3 | Dec 31 | Dec 30 | Dec 27 | Dec 25 | Dec 20 | Dec 11 |
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) | Nov 10 | Nov 26 | Dec 13 |
| Freeze (32°F) | Nov 24 | Dec 11 | Jan 12 |
| Hard (28°F) | Dec 4 | Dec 23 | Jan 19 |
| Severe (24°F) | Dec 9 | Dec 28 | Jan 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 10 | Nov 15 | Nov 19 | Nov 22 | Nov 26 | Nov 30 | Dec 2 | Dec 6 | Dec 13 |
| 32°F | Nov 24 | Dec 1 | Dec 3 | Dec 7 | Dec 11 | Dec 15 | Dec 21 | Jan 1 | Jan 12 |
| 28°F | Dec 4 | Dec 10 | Dec 14 | Dec 19 | Dec 23 | Dec 29 | Jan 3 | Jan 7 | Jan 19 |
| 24°F | Dec 9 | Dec 15 | Dec 21 | Dec 26 | Dec 28 | Dec 30 | Jan 3 | Jan 7 | Jan 15 |
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: Vacaville, Ca, about 4.2 miles away@if(!empty($station['elevation_ft'])), at 110 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 Allendale, CA?
On average, the last spring frost (32°F) around Allendale, CA is about Jan 31. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 30.
When is the first frost in the fall?
The first fall frost around Allendale, CA typically arrives about Dec 11. 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 31 on average, or Dec 30 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 318 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 95688 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026