Frost Dates for San Juan, TX
In San Juan, TX, the average last spring frost is around Jan 9 and the average first fall frost around Jan 1, for a growing season of about 365 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 Mcallen, TX weather station, 6 miles away, elevation 100 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 | Dec 8 |
| 20% | Feb 4 | Dec 14 |
| 30% | Jan 30 | Dec 22 |
| 40% | Jan 19 | Dec 28 |
| 50% | Jan 9 | Jan 1 |
| 60% | Jan 3 | Jan 5 |
| 70% | Dec 31 | Jan 13 |
| 80% | Dec 24 | Jan 26 |
| 90% | Dec 14 | Feb 4 |
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) | Jan 27 | Dec 19 |
| Frost / freeze (32°F) | Jan 9 | Jan 1 |
| Hard freeze (28°F) | Jan 4 | Jan 2 |
Planting calendar for San Juan
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 Nov 6 – Dec 4
Fall sowing Nov 6 – Nov 27
Fall sowing Oct 23 – Nov 6
Sow or transplant Dec 12 – Dec 26
Fall sowing Oct 23 – Nov 20
Transplant Dec 26 – Jan 9
Fall sowing Oct 9 – Oct 23
Transplant Dec 19 – Jan 2
Fall sowing Oct 9 – Oct 23
Fall sowing Oct 9 – Oct 23
Fall sowing Nov 20 – Dec 11
Fall sowing Oct 23 – Nov 6
Plant Dec 12 – Dec 26
Based on the average last frost (Jan 9) and first frost (Jan 1). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.