Last frost date in Rialto, California
January 10
Average last frost in spring. In an early year (1 in 10) it's over by December 20; in a late year (1 in 10) it comes after February 17.
January 2
Average first frost in fall. 1 year in 10 it comes by December 11.
A 32°F night happens here about 5 years in 10; in those years these are the usual dates.
Source: NOAA U.S. Climate Normals 1991–2020, station Riverside Citrus Exp (USC00047473), 10.5 miles from Rialto, elevation 986 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
This station is also the nearest one for Colton and Grand Terrace, so their frost dates are the same as Rialto's.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Dec 20 | Jan 10 | Feb 17 |
| First frost in fall | Dec 11 | Jan 2 | Feb 7 |
Frost-free days in an average year: 365
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | 10 years in 10 | Feb 11 | Dec 13 |
| Frost (32°F) | 5 years in 10 | Jan 10 | Jan 2 |
| Hard freeze (28°F) | Under 1 year in 20 | — | — |
Nights at 32°F or colder in an average year: 1.7
What to plant now in Rialto
- Swiss chardJune 1 – Dec 31Now
- BeetsSept 1 – Dec 31Now
- Broccoli plantsSept 1 – Dec 31Now
- Brussels sprouts plantsSept 1 – Dec 31Now
- Cabbage plantsSept 1 – Dec 31Now
- Chinese cabbageSept 1 – Dec 1Now
- Collards plantsSept 1 – Dec 31Now
- EndiveSept 1 – Dec 31Now
- Florence fennelSept 1 – Dec 1Now
- KaleSept 1 – Dec 31Now
- KohlrabiSept 1 – Dec 31Now
- ParsleySept 1 – Dec 31Now
- ParsnipsSept 1 – Dec 1Now
- SalsifySept 1 – Oct 31Now
- Snap beansSept 1 – Nov 1Now
- SorrelSept 1 – Dec 31Now
- TomatoesSept 1 – Nov 1Now
- CarrotsSept 15 – Dec 1Now
- Cauliflower plantsSept 15 – Nov 1Now
- GarlicSept 15 – Nov 15Now
- Head lettuce plantsSept 15 – Dec 31Now
- Leaf lettuceSept 15 – Dec 31Now
- LeeksSept 15 – Nov 1Now
- Mustard greensSept 15 – Dec 1Now
- Onion seedSept 15 – Nov 1Now
- ShallotsSept 15 – Nov 1Now
- Celery and celeriac plantsOct 1 – Dec 31Now
- Corn saladOct 1 – Dec 31Now
- DandelionOct 1 – Dec 31Now
- Garden peasOct 1 – Dec 31Now
- Onion plants plantsOct 1 – Dec 31Now
- RadishesOct 1 – Dec 31Now
- SpinachOct 1 – Dec 31Now
- TurnipsOct 1 – Dec 31Now
- Upland cressOct 1 – Dec 31Now
- RutabagaOct 15 – Nov 15Now
- Chervil and chivesNov 1 – Dec 31Soon
- Onion setsNov 1 – Dec 31Soon
- Fall planting calendar for an average first frost around December 20 Rialto: January 2
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in California
- Fontana 4 mi · last frost Jan 4
- San Bernardino 6 mi · last frost Jan 27
- Jurupa Valley 9 mi · last frost Jan 9
- Riverside 12 mi · last frost Jan 9
- Hesperia 20 mi · last frost Feb 28
Updated