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 03102
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 03102 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Massabesic Lake, NH, is 5 miles from the ZIP's center: its last spring frost comes after April 30 in half of years and after May 14 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 |
|---|---|---|---|---|---|---|
| Massabesic Lake, NH | 5 mi | 253 ft | April 30 | May 14 | October 11 | 5b |
| Manchester, NHManchester Airport | 6 mi | 225 ft | April 21 | May 6 | October 19 | 6b |
| Concord, NHConcord Municipal Airport | 13 mi | 346 ft | May 8 | May 22 | October 3 | 5b |
| Weare, NH | 13 mi | 720 ft | May 2 | May 14 | October 8 | – |
| Milford, NH | 14 mi | 320 ft | May 3 | May 15 | October 5 | – |
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 Massabesic Lake
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 24 | May 17 | May 12 | April 30 | October 2 | September 20 |
| 32°F | May 14 | May 4 | April 30 | April 19 | October 11 | September 30 |
| 28°F (hard freeze) | May 2 | April 23 | April 17 | April 6 | October 24 | October 8 |
| 24°F | April 18 | April 10 | April 5 | March 25 | November 5 | October 20 |
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.