Last spring frost
May 11
Frost Dates for Glennville, CA
First fall frost
Oct 17
Growing season
155 days
Hardiness zone
8b
In an average year around Glennville, CA, the last spring frost (32°F) is about May 11 and the first fall frost is about Oct 17, giving roughly a 155-day growing season. To be safe most years, wait until Apr 21 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 18 | Jun 3 | May 14 |
| Freeze (32°F) | Jun 6 | May 11 | Apr 21 |
| Hard (28°F) | May 11 | Apr 19 | Mar 28 |
| Severe (24°F) | Apr 18 | Mar 23 | Feb 15 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 18 | Jun 12 | Jun 9 | Jun 6 | Jun 3 | Jun 1 | May 28 | May 22 | May 14 |
| 32°F | Jun 6 | May 30 | May 23 | May 17 | May 11 | May 5 | May 1 | Apr 27 | Apr 21 |
| 28°F | May 11 | May 2 | Apr 27 | Apr 23 | Apr 19 | Apr 14 | Apr 9 | Apr 5 | Mar 28 |
| 24°F | Apr 18 | Apr 10 | Apr 4 | Mar 30 | Mar 23 | Mar 16 | Mar 9 | Feb 28 | Feb 15 |
| 20°F | Mar 18 | Mar 6 | Feb 27 | Feb 20 | Feb 12 | Feb 5 | Jan 28 | Jan 16 | Jan 3 |
| 16°F | Feb 25 | Feb 12 | Feb 3 | Jan 22 | Jan 12 | Jan 4 | Dec 31 | Dec 24 | Dec 14 |
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 13 | Oct 2 | Oct 19 |
| Freeze (32°F) | Sep 30 | Oct 17 | Nov 4 |
| Hard (28°F) | Oct 15 | Nov 2 | Nov 19 |
| Severe (24°F) | Oct 30 | Nov 20 | Dec 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 13 | Sep 20 | Sep 25 | Sep 29 | Oct 2 | Oct 5 | Oct 9 | Oct 14 | Oct 19 |
| 32°F | Sep 30 | Oct 6 | Oct 10 | Oct 15 | Oct 17 | Oct 21 | Oct 24 | Oct 29 | Nov 4 |
| 28°F | Oct 15 | Oct 21 | Oct 26 | Oct 30 | Nov 2 | Nov 5 | Nov 10 | Nov 14 | Nov 19 |
| 24°F | Oct 30 | Nov 5 | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 7 |
| 20°F | Nov 18 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 10 | Dec 15 | Dec 24 | Jan 5 |
| 16°F | Nov 29 | Dec 4 | Dec 12 | Dec 17 | Dec 22 | Dec 30 | Jan 4 | Jan 15 | Feb 4 |
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: Glennville, Ca, about 2.2 miles away@if(!empty($station['elevation_ft'])), at 3,140 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 Glennville, CA?
On average, the last spring frost (32°F) around Glennville, CA is about May 11. In cooler years it can run later, so for a safer bet many gardeners wait until Apr 21.
When is the first frost in the fall?
The first fall frost around Glennville, CA typically arrives about Oct 17. 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 11 on average, or Apr 21 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 155 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 93226 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026