Last spring frost
Feb 23
Frost Dates for Greenfield, CA
First fall frost
Nov 22
Growing season
271 days
Hardiness zone
9b
In an average year around Greenfield, CA, the last spring frost (32°F) is about Feb 23 and the first fall frost is about Nov 22, giving roughly a 271-day growing season. To be safe most years, wait until Jan 19 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 29 | Apr 7 | Mar 5 |
| Freeze (32°F) | Mar 31 | Feb 23 | Jan 19 |
| Hard (28°F) | Feb 21 | Jan 22 | Dec 18 |
| Severe (24°F) | Jan 29 | Dec 31 | Dec 6 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | Apr 22 | Apr 16 | Apr 11 | Apr 7 | Apr 1 | Mar 27 | Mar 17 | Mar 5 |
| 32°F | Mar 31 | Mar 16 | Mar 6 | Feb 28 | Feb 23 | Feb 17 | Feb 9 | Feb 1 | Jan 19 |
| 28°F | Feb 21 | Feb 10 | Feb 4 | Jan 31 | Jan 22 | Jan 14 | Jan 5 | Dec 30 | Dec 18 |
| 24°F | Jan 29 | Jan 16 | Jan 8 | Jan 3 | Dec 31 | Dec 26 | Dec 21 | Dec 15 | Dec 6 |
| 20°F | Jan 11 | Jan 2 | Dec 31 | Dec 28 | Dec 23 | Dec 19 | Dec 13 | Dec 9 | Dec 5 |
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 17 | Nov 4 | Nov 22 |
| Freeze (32°F) | Nov 1 | Nov 22 | Dec 11 |
| Hard (28°F) | Nov 19 | Dec 6 | Jan 10 |
| Severe (24°F) | Dec 1 | Dec 17 | Jan 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 17 | Oct 24 | Oct 28 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 22 |
| 32°F | Nov 1 | Nov 8 | Nov 13 | Nov 18 | Nov 22 | Nov 25 | Nov 30 | Dec 3 | Dec 11 |
| 28°F | Nov 19 | Nov 25 | Nov 30 | Dec 2 | Dec 6 | Dec 11 | Dec 18 | Dec 30 | Jan 10 |
| 24°F | Dec 1 | Dec 4 | Dec 7 | Dec 13 | Dec 17 | Dec 23 | Dec 30 | Jan 3 | Jan 15 |
| 20°F | Dec 3 | Dec 5 | Dec 10 | Dec 14 | Dec 21 | Dec 24 | Dec 28 | Jan 1 | 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: King City, Ca, about 14.9 miles away@if(!empty($station['elevation_ft'])), at 320 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 Greenfield, CA?
On average, the last spring frost (32°F) around Greenfield, CA is about Feb 23. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 19.
When is the first frost in the fall?
The first fall frost around Greenfield, CA typically arrives about Nov 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 Feb 23 on average, or Jan 19 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 271 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 93927 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026