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 35020
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 35020 in zone 8a (the coldest night of a typical year: 10 to 15°F).
The nearest station, Bessemer, AL, is 3 miles from the ZIP's center: its last spring frost comes after March 23 in half of years and after April 11 in one year in ten. By the USDA's method its plant hardiness zone is 8a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Bessemer, AL3 mi WSW | 3 mi | 445 ft | March 23 | April 11 | November 10 | 8a |
| Helena, AL | 11 mi | 480 ft | March 19 | April 9 | November 8 | 8b |
| Birmingham, ALBirmingham Airport | 16 mi | 615 ft | March 21 | April 8 | November 11 | 8a |
| Alabaster, ALAlabaster Shelby County Airport | 19 mi | 565 ft | March 12 | March 31 | November 16 | 8b |
| Bankhead Lock and Dam, AL | 23 mi | 280 ft | March 20 | April 9 | November 11 | – |
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 Bessemer
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 21 | April 13 | April 6 | March 21 | November 1 | October 18 |
| 32°F | April 11 | March 31 | March 23 | March 3 | November 10 | October 27 |
| 28°F (hard freeze) | March 28 | March 16 | March 9 | February 15 | November 23 | November 4 |
| 24°F | March 15 | March 4 | February 23 | January 25 | December 6 | November 15 |
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.