Frost Dates for Petaluma, CA
In Petaluma, CA, the average last spring frost is around Feb 28 and the average first fall frost around Nov 25, for a growing season of about 271 days. For frost-tender plants, wait until Apr 6, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Petaluma Airport, CA weather station, 2 miles away, elevation 20 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% | Apr 6 | Nov 9 |
| 20% | Mar 26 | Nov 14 |
| 30% | Mar 13 | Nov 18 |
| 40% | Mar 6 | Nov 22 |
| 50% | Feb 28 | Nov 25 |
| 60% | Feb 23 | Nov 29 |
| 70% | Feb 14 | Dec 2 |
| 80% | Feb 4 | Dec 7 |
| 90% | Jan 24 | Dec 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) | Apr 6 | Nov 10 |
| Frost / freeze (32°F) | Feb 28 | Nov 25 |
| Hard freeze (28°F) | Jan 17 | Dec 9 |
Planting calendar for Petaluma
Transplant Mar 7 – Mar 21
Transplant Mar 14 – Mar 28
Transplant Mar 14 – Mar 28
Transplant Mar 7 – Mar 21
Sow or transplant Mar 7 – Mar 21
Sow or transplant Mar 7 – Mar 21
Sow or transplant Mar 14 – Mar 28
Sow or transplant Jan 31 – Feb 14
Fall sowing Sep 30 – Oct 28
Fall sowing Sep 30 – Oct 21
Fall sowing Sep 16 – Sep 30
Sow or transplant Jan 31 – Feb 14
Fall sowing Sep 16 – Oct 14
Transplant Feb 14 – Feb 28
Fall sowing Sep 2 – Sep 16
Transplant Feb 7 – Feb 21
Fall sowing Sep 2 – Sep 16
Fall sowing Sep 2 – Sep 16
Fall sowing Oct 14 – Nov 4
Fall sowing Sep 16 – Sep 30
Plant Jan 31 – Feb 14
Based on the average last frost (Feb 28) and first frost (Nov 25). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.