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 63368
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 63368 in zone 6b (the coldest night of a typical year: -5 to 0°F).
The nearest station, Weldon Spring, MO, is 4 miles from the ZIP's center: its last spring frost comes after April 10 in half of years and after April 26 in one year in ten. By the USDA's method its plant hardiness zone is 6b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Weldon Spring, MOWeldon Spring NWS | 4 mi | 610 ft | April 10 | April 26 | October 26 | 6b |
| St. Peters, MOSt Peters (2 mi SE) | 8 mi | 575 ft | April 9 | April 25 | October 26 | 7a |
| St Louis Spirit of St. Louis Airport, MO | 8 mi | 462 ft | April 12 | April 27 | October 23 | 6b |
| St Charles (7 mi SSW), MO | 12 mi | 450 ft | April 4 | April 21 | October 29 | 6b |
| St Charles Elm Point, MO | 12 mi | 472 ft | April 8 | April 24 | October 29 | 6b |
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 Weldon Spring
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 6 | April 29 | April 22 | April 8 | October 16 | October 1 |
| 32°F | April 26 | April 16 | April 10 | March 26 | October 26 | October 12 |
| 28°F (hard freeze) | April 15 | April 4 | March 31 | March 12 | November 5 | October 22 |
| 24°F | April 3 | March 26 | March 19 | March 2 | November 17 | November 2 |
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.