USDA Hardiness Zone 10a
Frost Dates for 91710 — Chino, California
NOAA 1991–2020 normals from Chino Airport, CA (650 ft), 4 miles southeast.
Updated
A freeze (32°F) reaches Chino in 85% of winters. When it does, the first fall frost comes around December 19 and the last spring frost around January 17; after February 22 the chance of another is under 9%.
- Last spring frost
- January 17
- First fall frost
- December 19
- Winters with a freeze
- 85%
- Hardiness zone
- 10a
50%, in freezing years
50%, in freezing years
32°F or below, 1991–2020
30 to 35°F (-1.1 to 1.7°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 18 observed
NOAA normal
Frost risk by date in Chino
In the 85% of winters that bring a 32°F night, half of springs at Chino Airport, CA see their last 32°F night by January 17; only one in ten is past it by December 18, and one in ten still has one after February 22. Counting the winters with no freeze at all, the risk of a 32°F night after February 22 is under 9% and after January 17 43%. The 36 days between the even-odds date and the one-in-ten date is wider than at 75% of the 220 California stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by December 19 in half of years, as early as November 27 one year in ten, and holds off past January 17 one year in ten. A hard freeze of 28°F is less common: it came in 29% of winters. The freeze-free season lasts 335 days in a typical year, longer than at 86% of the 219 California stations; it reaches 365 days one year in ten and falls short of 293 one year in ten. On average 11 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 38 days longer, to about February 24, and return around December 1. A 24°F night is unusual: 2% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jan 21 | Feb 3 | Feb 12 | Feb 18 | Feb 24 | Feb 28 | Mar 6 | Mar 15 | Mar 29 |
| 32°F85% of yrs | Dec 18 | Dec 30 | Jan 5 | Jan 11 | Jan 17 | Jan 28 | Feb 3 | Feb 11 | Feb 22 |
| 28°F29% of yrs | too rare for a date | ||||||||
| 24°F2% of yrs | too rare for a date | ||||||||
| Low | 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°F85% of yrs | Nov 27 | Dec 5 | Dec 10 | Dec 14 | Dec 19 | Dec 23 | Dec 28 | Jan 2 | Jan 17 |
| 28°F29% of yrs | too rare for a date | ||||||||
| 24°F2% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Chino Airport, CA, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 91710 →Compare Chino with another place →
Weather by month in Chino
August is the warmest month at Chino Airport, CA, averaging 96°F by day and 63°F at night; December is the coldest at 69°F and 40°F. From March to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 25% of years.
Warmth for growing adds up to 5,949 growing degree days a year (base 50°F), more than at 89% of the 283 California stations. 38% of them (2,286) have built up by the end of June, and August adds the most, 922. Precipitation totals 10.1 inches a year, most in February (2.7") and least in June (0.0"); May to September bring 4% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 70 | 42 | 2.2 | 51% | 3 | 186 |
| Feb | 70 | 43 | 2.7 | 25% | 2 | 186 |
| Mar | 73 | 46 | 1.4 | 4% | <1 | 287 |
| Apr | 77 | 49 | 0.6 | 0% | <1 | 386 |
| May | 81 | 54 | 0.2 | 0% | 0 | 549 |
| Jun | 88 | 59 | 0.0 | 0% | 0 | 692 |
| Jul | 94 | 63 | 0.1 | 0% | 0 | 877 |
| Aug | 96 | 63 | 0.0 | 0% | 0 | 922 |
| Sep | 93 | 60 | 0.1 | 0% | 0 | 796 |
| Oct | 85 | 53 | 0.5 | 0% | 0 | 586 |
| Nov | 76 | 45 | 0.6 | 13% | 1 | 323 |
| Dec | 69 | 40 | 1.7 | 60% | 5 | 158 |
Monthly normals 1991–2020 at Chino Airport, CA (650 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Ontario International Airport, CA, 6 miles northeast of Chino and 299 feet higher, has a 32°F night in 41% of winters against 85% here, and a coolest-month low 4°F warmer (44°F).
When it snows in Chino, California
Measurable snow is rare here: only 0 of 18 winters from 1991 to 2020 recorded 0.1 inch or more at Covina City Yard Fc387b, CA, 12.2 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 91710 is 4 miles from Chino Airport, CA, which stands at 650 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 91710 in zone 10a, the band where the coldest night of the year averaged 30 to 35°F (-1.1 to 1.7°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across California →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.