Frost dates for 78212San Antonio, TX
The average last spring frost in San Antonio is February 25 and the average first fall frost is November 28, giving a typical growing season of about 277 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 25
- Average first fall frost
- Nov 28
- Growing season
- 277 days
Safer after Mar 19 (1-in-10 risk)
Possible by Nov 7 (1-in-10 risk)
First frost typically in 26 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 18 · Mar 10 · Apr 2 | Oct 30 · Nov 16 · Dec 3 | 251 days | 100% |
| Frost / freeze (32°F) | Jan 28 · Feb 25 · Mar 19 | Nov 7 · Nov 28 · Dec 21 | 277 days | 100% |
| Hard freeze (28°F) | Dec 31 · Feb 5 · Mar 5 | Nov 19 · Dec 15 · Jan 20 | 315 days | 95% |
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 25 – Apr 2 |
| Tomatoes | Transplant outdoors | Mar 13 – Aug 8 |
| Peppers | Start seeds indoors | Jan 25 – Feb 25 |
| Peppers | Transplant outdoors | Mar 27 – Apr 27 |
| Eggplant | Start seeds indoors | Feb 11 – Mar 12 |
| Eggplant | Transplant outdoors | Mar 27 – Apr 27 |
| Cucumbers | Sow outdoors | Mar 27 – Aug 18 |
| Summer squash | Sow outdoors | Mar 13 – Apr 27 |
| Winter squash & pumpkins | Sow outdoors | Mar 27 – Apr 27 |
| Snap beans | Sow outdoors | Mar 13 – Sep 10 |
| Sweet corn | Sow outdoors | Mar 13 – Aug 8 |
| Watermelon & cantaloupe | Sow outdoors | Mar 27 – Apr 27 |
| Okra | Sow outdoors | Mar 20 – Apr 12 |
| Peas | Sow outdoors (spring) | Jan 25 – Mar 12 |
| Potatoes | Plant outdoors (spring) | Jan 25 – Mar 27 |
| Onions | Start seeds indoors (spring) | Dec 14 – Jan 10 |
| Onions | Transplant outdoors (spring) | Feb 11 – Mar 12 |
| Broccoli | Start seeds indoors (spring) | Jan 7 – Feb 10 |
| Broccoli | Transplant outdoors (spring) | Feb 11 – Mar 12 |
| Broccoli | Start seeds indoors (fall) | Jul 29 – Aug 8 |
| Broccoli | Transplant outdoors (fall) | Aug 28 – Sep 8 |
| Cabbage | Start seeds indoors (spring) | Dec 28 – Jan 25 |
| Cabbage | Transplant outdoors (spring) | Jan 25 – Feb 25 |
| Cabbage | Start seeds indoors (fall) | Jul 19 – Aug 18 |
| Cabbage | Transplant outdoors (fall) | Aug 18 – Sep 18 |
| Leaf lettuce | Sow outdoors (spring) | Jan 25 – Apr 12 |
| Leaf lettuce | Sow outdoors (fall) | Aug 18 – Oct 4 |
| Spinach | Sow outdoors (spring) | Jan 18 – Mar 3 |
| Spinach | Sow outdoors (fall) | Sep 4 – Oct 9 |
| Radishes | Sow outdoors (spring) | Jan 25 – Mar 17 |
| Radishes | Sow outdoors (fall) | Aug 18 – Oct 19 |
| Kale | Sow outdoors (spring) | Feb 11 – Mar 3 |
| Kale | Sow outdoors (fall) | Aug 11 – Sep 18 |
| Carrots | Sow outdoors (spring) | Feb 25 – Apr 12 |
| Carrots | Sow outdoors (fall) | Jul 19 – Sep 3 |
| Garlic | Plant outdoors (fall) | Nov 18 – Dec 19 |
Where these dates come from
ZIP code 78212 is matched to the NOAA station San Antonio Incarnate Word, TX, 4 km away, at 700 ft elevation (21 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| San Antonio Incarnate Word, TX (used) | 700 ft | Feb 25 | Nov 28 |
| San Antonio Kelly Afb, TX | 682 ft | Feb 22 | Dec 2 |
| San Antonio Stinson Ap, TX | 571 ft | Feb 20 | Dec 3 |
| San Antonio Intl Ap, TX | 789 ft | Feb 26 | Nov 28 |
Frost dates near San Antonio
- San Antonio, TX 78284 · last Feb 25, first Nov 28
- Jbsa Ft Sam Houston, TX 78234 · last Feb 25, first Nov 28
- Jbsa Lackland, TX 78236 · last Feb 25, first Nov 28
- Converse, TX 78109 · last Feb 25, first Nov 28
- Universal City, TX 78148 · last Feb 21, first Dec 5
- Macdona, TX 78054 · last Feb 20, first Dec 3
- Adkins, TX 78101 · last Feb 20, first Dec 3
- Von Ormy, TX 78073 · last Feb 20, first Dec 3
Frequently asked questions
- When is the last frost in San Antonio, TX?
- For ZIP code 78212, the average last spring frost (32°F) is February 25, based on NOAA 1991-2020 climate normals for the San Antonio Incarnate Word, TX weather station. There is a 1-in-10 chance of a frost after March 19.
- When is the first frost in San Antonio, TX?
- The average first fall frost (32°F) is November 28. There is a 1-in-10 chance of frost by November 7, so tender plants are at risk from that point on.
- How long is the growing season in 78212?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 277 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.