Frost dates by ZIP code: The nearest NOAA stations to your ZIP, 1991-2020 normals
Enter a five-digit ZIP code. PlainClimate finds its center (Census Bureau 2024) and the five nearest NOAA stations with frost dates, and shows each station's last spring and first autumn 32°F dates with its distance and elevation.
Frost dates near ZIP 78255
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 78255 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Boerne, TX, is 11 miles from the ZIP's center: its last spring frost comes after March 15 in half of years and after April 8 in one year in ten. By the USDA's method its plant hardiness zone is 8b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Boerne, TX | 11 mi | 1,445 ft | March 15 | April 8 | November 13 | 8b |
| San Antonio, TXSan Antonio International Airport | 13 mi | 789 ft | February 26 | March 17 | November 28 | 9a |
| San Antonio/Seaworld, TX | 14 mi | 940 ft | February 18 | March 16 | December 9 | – |
| San Antonio Incarnate Word, TX | 17 mi | 700 ft | February 25 | March 19 | November 28 | 9a |
| San Antonio Kelly Air Force Base, TX | 19 mi | 682 ft | February 22 | March 12 | December 2 | – |
Frost comes later in spring at higher and colder stations and earlier in low, open ground: prefer a station at a similar elevation to yours. Hardiness zone in the table: the USDA's rule (the average of each year's coldest night, 1991-2020) applied to the station's own record.
Every frost threshold at Boerne
NOAA publishes the dates for several temperatures and odds. A 30% spring date means a 3-in-10 chance of a later frost (the convention almanacs use); 50% is the median; 10% the cautious date.
| Threshold | Spring, 10% | Spring, 30% | Spring, 50% | Spring, 90% | Autumn, 50% | Autumn, 10% |
|---|---|---|---|---|---|---|
| 36°F (light frost) | April 22 | April 9 | April 1 | March 9 | November 4 | October 21 |
| 32°F | April 8 | March 27 | March 15 | February 23 | November 13 | October 31 |
| 28°F (hard freeze) | March 23 | March 11 | March 2 | January 31 | November 27 | November 5 |
| 24°F | March 11 | February 28 | February 13 | December 31 | December 11 | November 17 |
Source: NOAA NCEI 1991-2020 annual normals; ZIP centers: Census Bureau 2024 Gazetteer; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. Autumn 10%: one year in ten has its first frost before this date.