Frost Dates for Suisun City, CA
In Suisun City, CA, the average last spring frost is around Jan 15 and the average first fall frost around Dec 14, for a growing season of about 336 days. For frost-tender plants, wait until Feb 16, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Fairfield, CA weather station, 4 miles away, elevation 40 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 16 | Nov 29 |
| 20% | Feb 2 | Dec 2 |
| 30% | Jan 28 | Dec 7 |
| 40% | Jan 21 | Dec 11 |
| 50% | Jan 15 | Dec 14 |
| 60% | Jan 9 | Dec 19 |
| 70% | Jan 3 | Dec 25 |
| 80% | Dec 29 | Jan 1 |
| 90% | Dec 22 | Jan 9 |
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 25 | Dec 1 |
| Frost / freeze (32°F) | Jan 15 | Dec 14 |
| Hard freeze (28°F) | Dec 31 | Dec 24 |
Planting calendar for Suisun City
Transplant Jan 22 – Feb 5
Transplant Jan 29 – Feb 12
Transplant Jan 29 – Feb 12
Transplant Jan 22 – Feb 5
Sow or transplant Jan 22 – Feb 5
Sow or transplant Jan 22 – Feb 5
Sow or transplant Jan 29 – Feb 12
Sow or transplant Dec 18 – Jan 1
Fall sowing Oct 19 – Nov 16
Fall sowing Oct 19 – Nov 9
Fall sowing Oct 5 – Oct 19
Sow or transplant Dec 18 – Jan 1
Fall sowing Oct 5 – Nov 2
Transplant Jan 1 – Jan 15
Fall sowing Sep 21 – Oct 5
Transplant Dec 25 – Jan 8
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 18 – Jan 1
Based on the average last frost (Jan 15) and first frost (Dec 14). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.