Frost Dates for San Bernardino, CA
In San Bernardino, CA, the average last spring frost is around Jan 27 and the average first fall frost around Dec 19, for a growing season of about 329 days. For frost-tender plants, wait until Feb 28, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Redlands, CA weather station, 9 miles away, elevation 1,410 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 28 | Dec 1 |
| 20% | Feb 19 | Dec 6 |
| 30% | Feb 10 | Dec 11 |
| 40% | Feb 3 | Dec 15 |
| 50% | Jan 27 | Dec 19 |
| 60% | Jan 16 | Dec 25 |
| 70% | Jan 7 | Jan 1 |
| 80% | Jan 1 | Jan 9 |
| 90% | Dec 21 | Jan 26 |
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) | Mar 2 | Dec 2 |
| Frost / freeze (32°F) | Jan 27 | Dec 19 |
| Hard freeze (28°F) | Jan 7 | Jan 1 |
Planting calendar for San Bernardino
Transplant Feb 3 – Feb 17
Transplant Feb 10 – Feb 24
Transplant Feb 10 – Feb 24
Transplant Feb 3 – Feb 17
Sow or transplant Feb 3 – Feb 17
Sow or transplant Feb 3 – Feb 17
Sow or transplant Feb 10 – Feb 24
Sow or transplant Dec 30 – Jan 13
Fall sowing Oct 24 – Nov 21
Fall sowing Oct 24 – Nov 14
Fall sowing Oct 10 – Oct 24
Sow or transplant Dec 30 – Jan 13
Fall sowing Oct 10 – Nov 7
Transplant Jan 13 – Jan 27
Fall sowing Sep 26 – Oct 10
Transplant Jan 6 – Jan 20
Fall sowing Sep 26 – Oct 10
Fall sowing Sep 26 – Oct 10
Fall sowing Nov 7 – Nov 28
Fall sowing Oct 10 – Oct 24
Plant Dec 30 – Jan 13
Based on the average last frost (Jan 27) and first frost (Dec 19). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.