Frost Dates for Concord, CA
In Concord, CA, the average last spring frost is around Jan 9 and the average first fall frost around Dec 14, for a growing season of about 343 days. For frost-tender plants, wait until Feb 12, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Concord Buchanan Fld, CA weather station, 3 miles away, elevation 18 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 12 | Nov 28 |
| 20% | Jan 31 | Dec 2 |
| 30% | Jan 23 | Dec 6 |
| 40% | Jan 16 | Dec 10 |
| 50% | Jan 9 | Dec 14 |
| 60% | Jan 3 | Dec 18 |
| 70% | Dec 30 | Dec 25 |
| 80% | Dec 25 | Jan 3 |
| 90% | Dec 16 | Jan 16 |
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 14 | Dec 1 |
| Frost / freeze (32°F) | Jan 9 | Dec 14 |
| Hard freeze (28°F) | Dec 30 | Dec 23 |
Planting calendar for Concord
Transplant Jan 16 – Jan 30
Transplant Jan 23 – Feb 6
Transplant Jan 23 – Feb 6
Transplant Jan 16 – Jan 30
Sow or transplant Jan 16 – Jan 30
Sow or transplant Jan 16 – Jan 30
Sow or transplant Jan 23 – Feb 6
Sow or transplant Dec 12 – Dec 26
Fall sowing Oct 19 – Nov 16
Fall sowing Oct 19 – Nov 9
Fall sowing Oct 5 – Oct 19
Sow or transplant Dec 12 – Dec 26
Fall sowing Oct 5 – Nov 2
Transplant Dec 26 – Jan 9
Fall sowing Sep 21 – Oct 5
Transplant Dec 19 – Jan 2
Fall sowing Sep 21 – Oct 5
Fall sowing Sep 21 – Oct 5
Fall sowing Nov 2 – Nov 23
Fall sowing Oct 5 – Oct 19
Plant Dec 12 – Dec 26
Based on the average last frost (Jan 9) and first frost (Dec 14). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.