Frost Dates for La Mesa, CA
In La Mesa, CA, the average last spring frost is around Jan 6 and the average first fall frost around Dec 21, for a growing season of about 350 days. For frost-tender plants, wait until Feb 7, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the El Cajon, CA weather station, 6 miles away, elevation 495 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 7 | Dec 1 |
| 20% | Jan 30 | Dec 7 |
| 30% | Jan 21 | Dec 12 |
| 40% | Jan 12 | Dec 17 |
| 50% | Jan 6 | Dec 21 |
| 60% | Dec 31 | Dec 25 |
| 70% | Dec 28 | Dec 30 |
| 80% | Dec 22 | Jan 4 |
| 90% | Dec 13 | Jan 15 |
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 6 | Dec 6 |
| Frost / freeze (32°F) | Jan 6 | Dec 21 |
| Hard freeze (28°F) | Dec 31 | Dec 30 |
Planting calendar for La Mesa
Transplant Jan 13 – Jan 27
Transplant Jan 20 – Feb 3
Transplant Jan 20 – Feb 3
Transplant Jan 13 – Jan 27
Sow or transplant Jan 13 – Jan 27
Sow or transplant Jan 13 – Jan 27
Sow or transplant Jan 20 – Feb 3
Sow or transplant Dec 9 – Dec 23
Fall sowing Oct 26 – Nov 23
Fall sowing Oct 26 – Nov 16
Fall sowing Oct 12 – Oct 26
Sow or transplant Dec 9 – Dec 23
Fall sowing Oct 12 – Nov 9
Transplant Dec 23 – Jan 6
Fall sowing Sep 28 – Oct 12
Transplant Dec 16 – Dec 30
Fall sowing Sep 28 – Oct 12
Fall sowing Sep 28 – Oct 12
Fall sowing Nov 9 – Nov 30
Fall sowing Oct 12 – Oct 26
Plant Dec 9 – Dec 23
Based on the average last frost (Jan 6) and first frost (Dec 21). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.