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 03860
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 03860 in zone 5a (the coldest night of a typical year: -20 to -15°F).
The nearest station, North Conway, NH, is 1 miles from the ZIP's center: its last spring frost comes after May 7 in half of years and after May 19 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 |
|---|---|---|---|---|---|---|
| North Conway, NH | 1 mi | 522 ft | May 7 | May 19 | October 5 | 5b |
| Fryeburg, MEFryeburg E Slopes Airport | 9 mi | 445 ft | May 17 | June 1 | September 25 | 4b |
| Tamworth 4, NH | 14 mi | 541 ft | May 16 | May 30 | September 26 | 5a |
| Pinkham Notch, NH | 16 mi | 2,025 ft | May 18 | June 1 | October 1 | 5a |
| Bridgton, ME3 mi NW | 19 mi | 508 ft | May 5 | May 17 | October 5 | 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 North Conway
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) | May 31 | May 23 | May 18 | May 6 | September 26 | September 13 |
| 32°F | May 19 | May 13 | May 7 | April 27 | October 5 | September 23 |
| 28°F (hard freeze) | May 9 | May 1 | April 26 | April 13 | October 17 | October 1 |
| 24°F | April 26 | April 17 | April 11 | April 2 | November 1 | October 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.