Last spring frost
Mar 3
Frost Dates for Cottonwood, CA
First fall frost
Nov 21
Growing season
261 days
Hardiness zone
9a
In an average year around Cottonwood, CA, the last spring frost (32°F) is about Mar 3 and the first fall frost is about Nov 21, giving roughly a 261-day growing season. To be safe most years, wait until Jan 31 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 26 | Apr 7 | Mar 9 |
| Freeze (32°F) | Apr 9 | Mar 3 | Jan 31 |
| Hard (28°F) | Mar 1 | Jan 27 | Dec 20 |
| Severe (24°F) | Feb 2 | Jan 1 | Dec 5 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 26 | Apr 21 | Apr 16 | Apr 12 | Apr 7 | Apr 3 | Mar 29 | Mar 20 | Mar 9 |
| 32°F | Apr 9 | Mar 31 | Mar 17 | Mar 9 | Mar 3 | Feb 27 | Feb 21 | Feb 13 | Jan 31 |
| 28°F | Mar 1 | Feb 20 | Feb 12 | Feb 2 | Jan 27 | Jan 19 | Jan 8 | Dec 31 | Dec 20 |
| 24°F | Feb 2 | Jan 22 | Jan 13 | Jan 6 | Jan 1 | Dec 27 | Dec 22 | Dec 15 | Dec 5 |
| 20°F | Jan 26 | Jan 19 | Jan 8 | Jan 2 | Dec 29 | Dec 21 | Dec 15 | Dec 10 | Dec 4 |
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 28 | Nov 9 | Nov 22 |
| Freeze (32°F) | Nov 7 | Nov 21 | Dec 7 |
| Hard (28°F) | Nov 20 | Dec 7 | Jan 5 |
| Severe (24°F) | Nov 30 | Dec 18 | Jan 22 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 14 | Nov 18 | Nov 22 |
| 32°F | Nov 7 | Nov 11 | Nov 16 | Nov 19 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 7 |
| 28°F | Nov 20 | Nov 26 | Dec 1 | Dec 4 | Dec 7 | Dec 12 | Dec 16 | Dec 24 | Jan 5 |
| 24°F | Nov 30 | Dec 3 | Dec 9 | Dec 14 | Dec 18 | Dec 25 | Jan 1 | Jan 7 | Jan 22 |
| 20°F | Dec 1 | Dec 7 | Dec 11 | Dec 15 | Dec 24 | Dec 31 | Jan 5 | Jan 11 | Jan 22 |
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: Redding Muni Ap, Ca, about 14.8 miles away@if(!empty($station['elevation_ft'])), at 497 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 Cottonwood, CA?
On average, the last spring frost (32°F) around Cottonwood, CA is about Mar 3. In cooler years it can run later, so for a safer bet many gardeners wait until Jan 31.
When is the first frost in the fall?
The first fall frost around Cottonwood, CA typically arrives about Nov 21. 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 Mar 3 on average, or Jan 31 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 261 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 96022 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026