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 66506
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 66506 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Manhattan station, KS, is 0 miles from the ZIP's center: its last spring frost comes after April 16 in half of years and after May 1 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Manhattan station, KS | 0 mi | 1,060 ft | April 16 | May 1 | October 19 | – |
| Tuttle Creek Lake, KS | 4 mi | 1,058 ft | April 22 | May 5 | October 20 | 6a |
| Manhattan (6 mi SSW), KS | 7 mi | 1,137 ft | April 19 | May 6 | October 17 | 6a |
| Manhattan, KSManhattan Municipal Airport | 7 mi | 1,057 ft | April 21 | May 6 | October 16 | 6a |
| Wamego, KS4 mi W | 11 mi | 1,166 ft | April 18 | May 2 | October 19 | 6a |
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 Manhattan station
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) | May 11 | May 2 | April 27 | April 13 | October 9 | September 25 |
| 32°F | May 1 | April 22 | April 16 | April 1 | October 19 | October 1 |
| 28°F (hard freeze) | April 24 | April 14 | April 6 | March 22 | October 29 | October 11 |
| 24°F | April 15 | April 4 | March 29 | March 11 | November 6 | October 21 |
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.