San Isidro, TX frost dates
Frost is light and occasional here — typically a few cold nights around midwinter (about 3 a year). Cover tender plants when frost is forecast.
How San Isidro compares
- In a typical year, frost nights in San Isidro fall between December 19 and January 22. In 1 year in 10 the first frost comes as early as November 26, or the last frost as late as March 5.
- Compared with Edinburg, TX, 47 km away, the last frost here is 14 days later than there.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | December 19 |
| 50% (median) | January 22 |
| 10% (safe for tender plants) | March 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | November 26 |
| 50% (median) | December 19 |
| 90% (late) | January 23 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Gardening where frost is rare
San Isidro, TX only freezes on a few winter nights, so the usual "plant after the last frost" rule doesn't apply. Heat and rainfall decide the seasons instead:
- Cool-season crops (lettuce, broccoli, peas, carrots) grow best from fall through late winter.
- Warm-season crops (tomatoes, peppers, beans, squash) do best planted in late winter to spring, and again in late summer for a fall crop — midsummer heat can stop tomatoes setting fruit.
- Heat lovers (okra, sweet potatoes, melons) can be planted through spring and early summer.
About these dates
Based on 1991–2020 NOAA climate normals for the Mccook, TX weather station, 37 km away (elevation 220 ft (67 m)).
Frost dates near San Isidro
- Delmita Jan 22 · Dec 19
- Santa Elena Jan 23 · Dec 28
- Linn Jan 22 · Dec 19
- Encino Feb 25 · Dec 1
- Edinburg Jan 8 · Jan 2
- Guerra Jan 19 · Dec 22
- Garciasville Jan 31 · Dec 17
- Penitas Jan 23 · Dec 28
- Hargill Jan 21 · Dec 23
- Rio Grande City Jan 31 · Dec 17
Frequently asked questions
When is the last frost in San Isidro, TX?
The median last spring frost in San Isidro, TX is January 22. There is still about a 10% chance of frost after March 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in San Isidro, TX?
The median first fall frost is December 19, with about a 10% chance of frost before November 26.
How long is the growing season in San Isidro, TX?
About 331 days between the median last spring frost and first fall frost.
What planting zone is San Isidro, TX?
San Isidro, TX is in USDA hardiness zone 9b.