Frost dates for 92337Fontana, CA
Frost occurs in about 45% of years near Fontana, based on NOAA 1991-2020 records for the Riverside Citrus Exp, CA station.
Frost occurs in about 45% of years. Frost-tender plants can usually grow year-round, but cover them if a rare cold snap is forecast.
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Jan 1 · Feb 11 · Mar 12 | Nov 25 · Dec 13 · Jan 8 | 312 days | 98% |
| Frost / freeze (32°F) | Dec 20 · Jan 10 · Feb 17 | Dec 11 · Jan 2 · Feb 7 | 365 days | 45% |
| Hard freeze (28°F) | — | — | 365 days | 2% |
Where these dates come from
ZIP code 92337 is matched to the NOAA station Riverside Citrus Exp, CA, 13.6 km away, at 986 ft elevation (5 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Riverside Citrus Exp, CA (used) | 986 ft | Jan 10 | Jan 2 |
| Riverside Muni Ap, CA | 805 ft | Jan 9 | Dec 30 |
| Ontario Intl Ap, CA | 949 ft | Jan 4 | Dec 30 |
| Riverside Fire Stn 3, CA | 840 ft | Jan 9 | Dec 25 |
Frost dates near Fontana
- Fontana, CA 92335 · last Jan 10, first Jan 2
- Riverside, CA 92509 · last Jan 9, first Dec 30
- Bloomington, CA 92316 · last Jan 10, first Jan 2
- Mira Loma, CA 91752 · last Jan 9, first Dec 30
- Guasti, CA 91743 · last Jan 4, first Dec 30
- Rialto, CA 92376 · last Jan 27, first Dec 19
- March Air Reserve Base, CA 92518 · last Jan 9, first Dec 25
- Rancho Cucamonga, CA 91729 · last Jan 8, first Dec 28
Frequently asked questions
- When is the last frost in Fontana, CA?
- Frost occurs in about 45% of years at the nearest NOAA station (Riverside Citrus Exp, CA), so there is no reliable average last frost date.
- When is the first frost in Fontana, CA?
- Frost occurs in about 45% of years at the nearest NOAA station.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.