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 70403
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 70403 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Hammond, LA, is 7 miles from the ZIP's center: its last spring frost comes after March 8 in half of years and after March 31 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 |
|---|---|---|---|---|---|---|
| Hammond, LA5 mi E | 7 mi | 35 ft | March 8 | March 31 | November 19 | 9a |
| Amite, LA | 16 mi | 170 ft | March 7 | March 31 | November 18 | 9a |
| Covington, LA4 mi NNW | 23 mi | 40 ft | March 12 | April 3 | November 18 | 8b |
| Reserve, LA | 30 mi | 15 ft | February 9 | March 11 | December 14 | – |
| New Orleans, LANew Orleans Airport | 37 mi | 4 ft | January 30 | February 27 | December 31 | 9b |
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 Hammond
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 16 | April 3 | March 25 | March 1 | November 6 | October 23 |
| 32°F | March 31 | March 18 | March 8 | February 12 | November 19 | November 3 |
| 28°F (hard freeze) | March 17 | March 3 | February 21 | January 20 | December 2 | November 14 |
| 24°F | March 6 | February 14 | February 1 | December 30 | December 29 | November 28 |
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.