Frost dates in San Antonio, Texas
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in San Antonio is February 26, and the average first fall frost is November 28, from NOAA's San Antonio Intl Airport station, 6 miles from the middle of San Antonio. 1 year in 10 the last frost comes after March 17, and the first one by November 7. That leaves about 275 frost-free days. San Antonio is in USDA planting zone 9a.
Weather stations around San Antonio
The first row is the date most people in San Antonio go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| San Antonio Intl Airport 6 mi away, 789 ft | February 26 1 in 10 after March 17 | November 28 1 in 10 by November 7 | 275 days |
| San Antonio Incarnate Word 3 mi away, 700 ft | February 25 1 in 10 after March 19 | November 28 1 in 10 by November 7 | 276 days |
| San Antonio Kelly AFB 7 mi away, 682 ft | February 22 1 in 10 after March 12 | December 2 1 in 10 by November 13 | 283 days |
| San Antonio Stinson Airport 9 mi away, 571 ft | February 20 1 in 10 after March 13 | December 3 1 in 10 by November 12 | 286 days |
| San Antonio/Seaworld 11 mi away, 940 ft | February 18 1 in 10 after March 16 | December 9 1 in 10 by November 17 | 294 days |
Distances are from the middle of San Antonio as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 78201, at the middle of the city.
Your exact ZIP code
San Antonio covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of Texas, station by station.
Other Texas cities: Houston · Dallas · Fort Worth · Austin · El Paso · Arlington · Corpus Christi · Plano · Lubbock · Laredo · Irving · Garland · Frisco · McKinney · Grand Prairie · Amarillo · Brownsville · Denton · Killeen · Mesquite · McAllen · Pasadena · Waco · Midland · Round Rock
Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer