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 35114
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 35114 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Helena, AL, is 4 miles from the ZIP's center: its last spring frost comes after March 19 in half of years and after April 9 in one year in ten. By the USDA's method its plant hardiness zone is 8b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Helena, AL | 4 mi | 480 ft | March 19 | April 9 | November 8 | 8b |
| Alabaster, ALAlabaster Shelby County Airport | 6 mi | 565 ft | March 12 | March 31 | November 16 | 8b |
| Bessemer, AL3 mi WSW | 14 mi | 445 ft | March 23 | April 11 | November 10 | 8a |
| Thorsby, ALThorsby Experiment Station | 24 mi | 680 ft | March 21 | April 10 | November 11 | – |
| Birmingham, ALBirmingham Airport | 25 mi | 615 ft | March 21 | April 8 | November 11 | 8a |
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 Helena
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 11 | April 3 | March 15 | October 30 | October 17 |
| 32°F | April 9 | March 29 | March 19 | February 26 | November 8 | October 26 |
| 28°F (hard freeze) | March 25 | March 12 | March 4 | February 8 | November 22 | November 3 |
| 24°F | March 12 | February 28 | February 17 | January 22 | December 5 | November 13 |
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.