Frost dates for 78211San Antonio, TX
The average last spring frost in San Antonio is February 20 and the average first fall frost is December 3, giving a typical growing season of about 291 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 20
- Average first fall frost
- Dec 3
- Growing season
- 291 days
Safer after Mar 13 (1-in-10 risk)
Possible by Nov 12 (1-in-10 risk)
First frost typically in 37 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Feb 8 · Mar 5 · Mar 27 | Nov 2 · Nov 21 · Dec 9 | 261 days | 100% |
| Frost / freeze (32°F) | Jan 20 · Feb 20 · Mar 13 | Nov 12 · Dec 3 · Jan 1 | 291 days | 100% |
| Hard freeze (28°F) | Dec 25 · Jan 30 · Mar 5 | Nov 24 · Dec 23 · Jan 24 | 330 days | 90% |
Planting calendar for San Antonio
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Jan 20 – Mar 28 |
| Tomatoes | Transplant outdoors | Mar 8 – Aug 13 |
| Peppers | Start seeds indoors | Jan 20 – Feb 20 |
| Peppers | Transplant outdoors | Mar 22 – Apr 22 |
| Eggplant | Start seeds indoors | Feb 6 – Mar 7 |
| Eggplant | Transplant outdoors | Mar 22 – Apr 22 |
| Cucumbers | Sow outdoors | Mar 22 – Aug 23 |
| Summer squash | Sow outdoors | Mar 8 – Apr 22 |
| Winter squash & pumpkins | Sow outdoors | Mar 22 – Apr 22 |
| Snap beans | Sow outdoors | Mar 8 – Sep 15 |
| Sweet corn | Sow outdoors | Mar 8 – Aug 13 |
| Watermelon & cantaloupe | Sow outdoors | Mar 22 – Apr 22 |
| Okra | Sow outdoors | Mar 15 – Apr 7 |
| Peas | Sow outdoors (spring) | Jan 20 – Mar 7 |
| Potatoes | Plant outdoors (spring) | Jan 20 – Mar 22 |
| Onions | Start seeds indoors (spring) | Dec 9 – Jan 5 |
| Onions | Transplant outdoors (spring) | Feb 6 – Mar 7 |
| Broccoli | Start seeds indoors (spring) | Jan 2 – Feb 5 |
| Broccoli | Transplant outdoors (spring) | Feb 6 – Mar 7 |
| Broccoli | Start seeds indoors (fall) | Aug 3 – Aug 13 |
| Broccoli | Transplant outdoors (fall) | Sep 2 – Sep 13 |
| Cabbage | Start seeds indoors (spring) | Dec 23 – Jan 20 |
| Cabbage | Transplant outdoors (spring) | Jan 20 – Feb 20 |
| Cabbage | Start seeds indoors (fall) | Jul 24 – Aug 23 |
| Cabbage | Transplant outdoors (fall) | Aug 23 – Sep 23 |
| Leaf lettuce | Sow outdoors (spring) | Jan 20 – Apr 7 |
| Leaf lettuce | Sow outdoors (fall) | Aug 23 – Oct 9 |
| Spinach | Sow outdoors (spring) | Jan 13 – Feb 26 |
| Spinach | Sow outdoors (fall) | Sep 9 – Oct 14 |
| Radishes | Sow outdoors (spring) | Jan 20 – Mar 12 |
| Radishes | Sow outdoors (fall) | Aug 23 – Oct 24 |
| Kale | Sow outdoors (spring) | Feb 6 – Feb 26 |
| Kale | Sow outdoors (fall) | Aug 16 – Sep 23 |
| Carrots | Sow outdoors (spring) | Feb 20 – Apr 7 |
| Carrots | Sow outdoors (fall) | Jul 24 – Sep 8 |
| Garlic | Plant outdoors (fall) | Nov 23 – Dec 24 |
Where these dates come from
ZIP code 78211 is matched to the NOAA station San Antonio Stinson Ap, TX, 9 km away, at 571 ft elevation (75 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| San Antonio Stinson Ap, TX (used) | 571 ft | Feb 20 | Dec 3 |
| San Antonio Kelly Afb, TX | 682 ft | Feb 22 | Dec 2 |
| San Antonio Incarnate Word, TX | 700 ft | Feb 25 | Nov 28 |
| San Antonio/Seaworld, TX | 940 ft | Feb 18 | Dec 9 |
Frost dates near San Antonio
- San Antonio, TX 78224 · last Feb 20, first Dec 3
- Jbsa Ft Sam Houston, TX 78234 · last Feb 25, first Nov 28
- Jbsa Lackland, TX 78236 · last Feb 25, first Nov 28
- Macdona, TX 78054 · last Feb 20, first Dec 3
- Von Ormy, TX 78073 · last Feb 20, first Dec 3
- Somerset, TX 78069 · last Feb 20, first Dec 3
- Atascosa, TX 78002 · last Feb 24, first Dec 2
- Elmendorf, TX 78112 · last Feb 20, first Dec 3
Frequently asked questions
- When is the last frost in San Antonio, TX?
- For ZIP code 78211, the average last spring frost (32°F) is February 20, based on NOAA 1991-2020 climate normals for the San Antonio Stinson Ap, TX weather station. There is a 1-in-10 chance of a frost after March 13.
- When is the first frost in San Antonio, TX?
- The average first fall frost (32°F) is December 3. There is a 1-in-10 chance of frost by November 12, so tender plants are at risk from that point on.
- How long is the growing season in 78211?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 291 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.