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 73145
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 73145 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Spencer, OK, is 9 miles from the ZIP's center: its last spring frost comes after April 2 in half of years and after April 18 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Spencer, OKSpencer 2 mi ENE Mesonet | 9 mi | 1,223 ft | April 2 | April 18 | November 5 | – |
| Oklahoma City, OKOklahoma City Will Rogers Airport | 11 mi | 1,285 ft | April 4 | April 20 | November 2 | 7b |
| Norman 2 mi NW Mesonet, OK | 13 mi | 1,181 ft | March 31 | April 17 | November 5 | – |
| Oklahoma City Post Airport, OK | 15 mi | 1,297 ft | April 2 | April 18 | November 4 | 7b |
| Norman, OK3 mi SSE | 17 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 Spencer
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 28 | April 20 | April 12 | March 26 | October 28 | October 14 |
| 32°F | April 18 | April 8 | April 2 | March 12 | November 5 | October 20 |
| 28°F (hard freeze) | April 6 | March 27 | March 17 | February 28 | November 13 | October 30 |
| 24°F | March 25 | March 12 | March 4 | February 16 | November 25 | November 5 |
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.