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 04073
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 04073 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Sanford, ME, is 4 miles from the ZIP's center: its last spring frost comes after May 16 in half of years and after May 29 in one year in ten. By the USDA's method its plant hardiness zone is 5b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Sanford, ME2 mi NNW | 4 mi | 289 ft | May 16 | May 29 | September 30 | 5b |
| Rochester, NHRochester Skyhaven Airport | 13 mi | 323 ft | April 30 | May 13 | October 9 | 6a |
| Cape Neddick, ME | 14 mi | 152 ft | May 1 | May 14 | October 14 | – |
| Kennebunkport, ME | 14 mi | 20 ft | May 9 | May 22 | October 3 | 6a |
| Hollis, ME | 17 mi | 304 ft | May 14 | May 28 | September 30 | 5a |
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 Sanford
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) | June 6 | June 1 | May 26 | May 15 | September 20 | September 6 |
| 32°F | May 29 | May 21 | May 16 | May 2 | September 30 | September 18 |
| 28°F (hard freeze) | May 17 | May 8 | May 2 | April 21 | October 7 | September 28 |
| 24°F | May 2 | April 25 | April 20 | April 6 | October 20 | October 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.