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 73139
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 73139 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Oklahoma City, OK, is 4 miles from the ZIP's center: its last spring frost comes after April 4 in half of years and after April 20 in one year in ten. By the USDA's method its plant hardiness zone is 7b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Oklahoma City, OKOklahoma City Will Rogers Airport | 4 mi | 1,285 ft | April 4 | April 20 | November 2 | 7b |
| Norman 2 mi NW Mesonet, OK | 11 mi | 1,181 ft | March 31 | April 17 | November 5 | – |
| Oklahoma City Post Airport, OK | 12 mi | 1,297 ft | April 2 | April 18 | November 4 | 7b |
| Spencer, OKSpencer 2 mi ENE Mesonet | 15 mi | 1,223 ft | April 2 | April 18 | November 5 | – |
| Norman, OK3 mi SSE | 15 mi | 1,128 ft | April 3 | April 18 | November 3 | 7b |
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 Oklahoma City
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 30 | April 21 | April 15 | March 31 | October 26 | October 12 |
| 32°F | April 20 | April 10 | April 4 | March 16 | November 2 | October 21 |
| 28°F (hard freeze) | April 7 | March 30 | March 21 | March 3 | November 11 | October 29 |
| 24°F | March 29 | March 16 | March 8 | February 20 | November 21 | November 4 |
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.