Last spring frost
Feb 18
Frost Dates for Winters, CA
First fall frost
Nov 30
Growing season
284 days
Hardiness zone
9b
In an average year around Winters, CA, the last spring frost (32°F) is about Feb 18 and the first fall frost is about Nov 30, giving roughly a 284-day growing season. To be safe most years, wait until Jan 17 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 13 | Mar 18 | Feb 24 |
| Freeze (32°F) | Mar 14 | Feb 18 | Jan 17 |
| Hard (28°F) | Feb 17 | Jan 14 | Dec 18 |
| Severe (24°F) | Jan 22 | Dec 31 | Dec 10 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 13 | Apr 5 | Mar 31 | Mar 25 | Mar 18 | Mar 14 | Mar 8 | Mar 2 | Feb 24 |
| 32°F | Mar 14 | Mar 7 | Mar 1 | Feb 25 | Feb 18 | Feb 12 | Feb 6 | Jan 30 | Jan 17 |
| 28°F | Feb 17 | Feb 3 | Jan 27 | Jan 20 | Jan 14 | Jan 8 | Jan 1 | Dec 28 | Dec 18 |
| 24°F | Jan 22 | Jan 15 | Jan 10 | Jan 5 | Dec 31 | Dec 30 | Dec 26 | Dec 19 | Dec 10 |
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 2 | Nov 15 | Nov 29 |
| Freeze (32°F) | Nov 15 | Nov 30 | Dec 18 |
| Hard (28°F) | Nov 28 | Dec 15 | Jan 12 |
| Severe (24°F) | Dec 4 | Dec 27 | Jan 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 2 | Nov 7 | Nov 10 | Nov 13 | Nov 15 | Nov 17 | Nov 20 | Nov 24 | Nov 29 |
| 32°F | Nov 15 | Nov 20 | Nov 23 | Nov 26 | Nov 30 | Dec 2 | Dec 6 | Dec 10 | Dec 18 |
| 28°F | Nov 28 | Dec 2 | Dec 6 | Dec 11 | Dec 15 | Dec 19 | Dec 26 | Jan 3 | Jan 12 |
| 24°F | Dec 4 | Dec 9 | Dec 15 | Dec 21 | Dec 27 | Dec 30 | Jan 2 | Jan 9 | Jan 16 |
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: Winters, Ca, about 5.7 miles away@if(!empty($station['elevation_ft'])), at 135 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 Winters, CA?
On average, the last spring frost (32°F) around Winters, CA is about Feb 18. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 17.
When is the first frost in the fall?
The first fall frost around Winters, CA typically arrives about Nov 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 Feb 18 on average, or Jan 17 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 284 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 95694 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026