Last spring frost
Apr 18
Frost Dates for Ramona, CA
First fall frost
Oct 26
Growing season
189 days
Hardiness zone
9a
In an average year around Ramona, CA, the last spring frost (32°F) is about Apr 18 and the first fall frost is about Oct 26, giving roughly a 189-day growing season. To be safe most years, wait until Mar 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) | Jun 25 | May 17 | Apr 24 |
| Freeze (32°F) | May 14 | Apr 18 | Mar 30 |
| Hard (28°F) | Apr 13 | Mar 14 | Feb 11 |
| Severe (24°F) | Mar 2 | Feb 5 | Jan 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 25 | Jun 8 | May 31 | May 24 | May 17 | May 11 | May 4 | Apr 30 | Apr 24 |
| 32°F | May 14 | May 2 | Apr 28 | Apr 22 | Apr 18 | Apr 15 | Apr 11 | Apr 6 | Mar 30 |
| 28°F | Apr 13 | Apr 5 | Mar 31 | Mar 22 | Mar 14 | Mar 6 | Feb 28 | Feb 23 | Feb 11 |
| 24°F | Mar 2 | Feb 25 | Feb 18 | Feb 12 | Feb 5 | Jan 31 | Jan 24 | Jan 14 | Jan 2 |
| 20°F | Feb 10 | Jan 31 | Jan 22 | Jan 12 | Jan 5 | Dec 31 | Dec 26 | Dec 20 | Dec 11 |
| 16°F | Jan 19 | Jan 7 | Dec 31 | Dec 28 | Dec 22 | Dec 19 | Dec 15 | Dec 11 | Dec 8 |
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 18 | Oct 8 | Oct 25 |
| Freeze (32°F) | Oct 9 | Oct 26 | Nov 13 |
| Hard (28°F) | Oct 25 | Nov 14 | Dec 2 |
| Severe (24°F) | Nov 11 | Dec 3 | Dec 26 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 18 | Sep 26 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 18 | Oct 25 |
| 32°F | Oct 9 | Oct 14 | Oct 18 | Oct 21 | Oct 26 | Oct 30 | Nov 3 | Nov 7 | Nov 13 |
| 28°F | Oct 25 | Oct 31 | Nov 5 | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Dec 2 |
| 24°F | Nov 11 | Nov 20 | Nov 27 | Dec 1 | Dec 3 | Dec 7 | Dec 12 | Dec 17 | Dec 26 |
| 20°F | Nov 26 | Dec 3 | Dec 8 | Dec 12 | Dec 16 | Dec 21 | Dec 27 | Jan 2 | Jan 17 |
| 16°F | Dec 5 | Dec 8 | Dec 12 | Dec 17 | Dec 20 | Dec 24 | Dec 29 | Jan 1 | 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: Henshaw Dam, Ca, about 3.5 miles away@if(!empty($station['elevation_ft'])), at 2,700 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 Ramona, CA?
On average, the last spring frost (32°F) around Ramona, CA is about Apr 18. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 30.
When is the first frost in the fall?
The first fall frost around Ramona, CA typically arrives about Oct 26. 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 Apr 18 on average, or Mar 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 189 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 92070 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026