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 78070
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 78070 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Canyon Lake, TX, is 13 miles from the ZIP's center: its last spring frost comes after March 1 in half of years and after March 22 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Canyon Lake, TXCanyon Dam | 13 mi | 1,000 ft | March 1 | March 22 | December 1 | 9a |
| Blanco, TX | 14 mi | 1,310 ft | March 20 | April 8 | November 10 | 8b |
| Boerne, TX | 21 mi | 1,445 ft | March 15 | April 8 | November 13 | 8b |
| New Braunfels, TX | 22 mi | 720 ft | March 8 | April 1 | November 18 | – |
| San Antonio, TXSan Antonio International Airport | 24 mi | 789 ft | February 26 | March 17 | November 28 | 9a |
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 Canyon Lake
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 4 | March 21 | March 12 | February 21 | November 16 | November 1 |
| 32°F | March 22 | March 8 | March 1 | January 31 | December 1 | November 9 |
| 28°F (hard freeze) | March 9 | February 24 | February 10 | January 4 | December 19 | November 23 |
| 24°F | February 28 | February 9 | January 25 | December 25 | January 5 | December 11 |
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.