Frost Dates for Colton, CA
In Colton, CA, the average last spring frost is around Jan 10 and the average first fall frost around Jan 2, for a growing season of about 365 days. For frost-tender plants, wait until Feb 17, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Riverside Citrus Exp, CA weather station, 6 miles away, elevation 986 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | Feb 17 | Dec 11 |
| 20% | Feb 3 | Dec 20 |
| 30% | Jan 25 | Dec 26 |
| 40% | Jan 16 | Dec 30 |
| 50% | Jan 10 | Jan 2 |
| 60% | Jan 5 | Jan 7 |
| 70% | Jan 2 | Jan 15 |
| 80% | Dec 29 | Jan 24 |
| 90% | Dec 20 | Feb 7 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | Feb 11 | Dec 13 |
| Frost / freeze (32°F) | Jan 10 | Jan 2 |
| Hard freeze (28°F) | — | — |
Planting calendar for Colton
Transplant Jan 17 – Jan 31
Transplant Jan 24 – Feb 7
Transplant Jan 24 – Feb 7
Transplant Jan 17 – Jan 31
Sow or transplant Jan 17 – Jan 31
Sow or transplant Jan 17 – Jan 31
Sow or transplant Jan 24 – Feb 7
Sow or transplant Dec 13 – Dec 27
Fall sowing Nov 7 – Dec 5
Fall sowing Nov 7 – Nov 28
Fall sowing Oct 24 – Nov 7
Sow or transplant Dec 13 – Dec 27
Fall sowing Oct 24 – Nov 21
Transplant Dec 27 – Jan 10
Fall sowing Oct 10 – Oct 24
Transplant Dec 20 – Jan 3
Fall sowing Oct 10 – Oct 24
Fall sowing Oct 10 – Oct 24
Fall sowing Nov 21 – Dec 12
Fall sowing Oct 24 – Nov 7
Plant Dec 13 – Dec 27
Based on the average last frost (Jan 10) and first frost (Jan 2). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.