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 62226
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 62226 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Belleville, IL, is 8 miles from the ZIP's center: its last spring frost comes after April 12 in half of years and after April 28 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 |
|---|---|---|---|---|---|---|
| Belleville, ILBelleville Siu Research | 8 mi | 450 ft | April 12 | April 28 | October 20 | 6b |
| Cahokia Heights, ILCahokia St Louis Airport | 9 mi | 413 ft | April 8 | April 23 | October 26 | 7a |
| Cahokia, IL | 11 mi | 400 ft | April 6 | April 20 | October 27 | 6b |
| St Louis Science Center, MO | 16 mi | 515 ft | April 1 | April 18 | November 4 | – |
| Alton, ILAlton - Melvin Price Lock and Dam | 24 mi | 405 ft | April 4 | April 19 | November 5 | – |
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 Belleville
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 8 | April 30 | April 23 | April 10 | October 9 | September 27 |
| 32°F | April 28 | April 19 | April 12 | March 28 | October 20 | October 3 |
| 28°F (hard freeze) | April 16 | April 6 | March 31 | March 14 | October 30 | October 15 |
| 24°F | April 6 | March 29 | March 21 | March 2 | November 10 | October 29 |
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.