Last spring frost
Jan 17
Frost Dates for Chino, CA
First fall frost
Dec 19
Growing season
335 days
Hardiness zone
10a
In an average year around Chino, CA, the last spring frost (32°F) is about Jan 17 and the first fall frost is about Dec 19, giving roughly a 335-day growing season. To be safe most years, wait until Dec 18 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) | Mar 29 | Feb 24 | Jan 21 |
| Freeze (32°F) | Feb 22 | Jan 17 | Dec 18 |
| Hard (28°F) | Jan 28 | Jan 3 | Dec 11 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 29 | Mar 15 | Mar 6 | Feb 28 | Feb 24 | Feb 18 | Feb 12 | Feb 3 | Jan 21 |
| 32°F | Feb 22 | Feb 11 | Feb 3 | Jan 28 | Jan 17 | Jan 11 | Jan 5 | Dec 30 | Dec 18 |
| 28°F | Jan 28 | Jan 18 | Jan 12 | Jan 7 | Jan 3 | Dec 31 | Dec 25 | Dec 20 | Dec 11 |
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 12 | Dec 1 | Dec 18 |
| Freeze (32°F) | Nov 27 | Dec 19 | Jan 17 |
| Hard (28°F) | Dec 7 | Dec 30 | Jan 23 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 12 | Nov 19 | Nov 24 | Nov 28 | Dec 1 | Dec 4 | Dec 8 | Dec 12 | Dec 18 |
| 32°F | Nov 27 | Dec 5 | Dec 10 | Dec 14 | Dec 19 | Dec 23 | Dec 28 | Jan 2 | Jan 17 |
| 28°F | Dec 7 | Dec 15 | Dec 21 | Dec 25 | Dec 30 | Jan 2 | Jan 6 | Jan 12 | Jan 23 |
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: Chino Ap, Ca, about 3.4 miles away@if(!empty($station['elevation_ft'])), at 650 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 Chino, CA?
On average, the last spring frost (32°F) around Chino, CA is about Jan 17. In cooler years it can run later, so for a safer bet many gardeners wait until Dec 18.
When is the first frost in the fall?
The first fall frost around Chino, CA typically arrives about Dec 19. 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 Jan 17 on average, or Dec 18 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 335 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 91710 Planting calendar → California frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026