Frost Dates for Brentwood, CA
In Brentwood, CA, the average last spring frost is around Jan 12 and the average first fall frost around Dec 19, for a growing season of about 343 days. For frost-tender plants, wait until Feb 1, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Antioch Pumping Plt #3, CA weather station, 4 miles away, elevation 60 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 1 | Nov 29 |
| 20% | Jan 28 | Dec 5 |
| 30% | Jan 22 | Dec 10 |
| 40% | Jan 16 | Dec 15 |
| 50% | Jan 12 | Dec 19 |
| 60% | Jan 7 | Dec 23 |
| 70% | Jan 2 | Dec 29 |
| 80% | Dec 29 | Jan 3 |
| 90% | Dec 20 | Jan 12 |
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 8 | Dec 4 |
| Frost / freeze (32°F) | Jan 12 | Dec 19 |
| Hard freeze (28°F) | Jan 2 | Dec 29 |
Planting calendar for Brentwood
Transplant Jan 19 – Feb 2
Transplant Jan 26 – Feb 9
Transplant Jan 26 – Feb 9
Transplant Jan 19 – Feb 2
Sow or transplant Jan 19 – Feb 2
Sow or transplant Jan 19 – Feb 2
Sow or transplant Jan 26 – Feb 9
Sow or transplant Dec 15 – Dec 29
Fall sowing Oct 24 – Nov 21
Fall sowing Oct 24 – Nov 14
Fall sowing Oct 10 – Oct 24
Sow or transplant Dec 15 – Dec 29
Fall sowing Oct 10 – Nov 7
Transplant Dec 29 – Jan 12
Fall sowing Sep 26 – Oct 10
Transplant Dec 22 – Jan 5
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 15 – Dec 29
Based on the average last frost (Jan 12) and first frost (Dec 19). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.