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 70809
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 70809 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Lsu Ben-Hur Farm, LA, is 6 miles from the ZIP's center: its last spring frost comes after February 28 in half of years and after March 21 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Lsu Ben-Hur Farm, LA | 6 mi | 21 ft | February 28 | March 21 | November 26 | 9a |
| Baton Rouge, LABaton Rouge Metro Airport | 11 mi | 64 ft | February 25 | March 19 | November 26 | 9a |
| Brusly, LA2 mi W | 12 mi | 20 ft | February 28 | March 21 | November 24 | 9a |
| Carville (2 mi SW), LA | 14 mi | 25 ft | February 9 | March 10 | December 13 | 9b |
| Donaldsonville, LA4 mi SW | 22 mi | 30 ft | February 21 | March 15 | December 5 | 9a |
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 Lsu Ben-Hur Farm
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 5 | March 25 | March 16 | February 21 | November 12 | October 29 |
| 32°F | March 21 | March 10 | February 28 | January 31 | November 26 | November 6 |
| 28°F (hard freeze) | March 10 | February 23 | February 7 | January 7 | December 16 | November 20 |
| 24°F | February 26 | February 2 | January 24 | December 24 | January 2 | December 5 |
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.