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 06850
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 06850 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Stamford, CT, is 5 miles from the ZIP's center: its last spring frost comes after April 17 in half of years and after May 2 in one year in ten. By the USDA's method its plant hardiness zone is 6b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Stamford, CT5 mi N | 5 mi | 190 ft | April 17 | May 2 | October 23 | 6b |
| Westchester County Airport, NY | 14 mi | 379 ft | April 12 | April 27 | October 31 | 7a |
| Bridgeport, CTIgor I Sikorsky Memorial Airport | 17 mi | 5 ft | April 5 | April 17 | November 6 | 7a |
| Danbury, CTDanbury Municipal Airport | 17 mi | 457 ft | May 1 | May 16 | October 14 | 6b |
| Centerport, NY | 17 mi | 30 ft | April 9 | April 23 | November 10 | 7b |
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 Stamford
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 16 | May 7 | April 30 | April 16 | October 12 | October 1 |
| 32°F | May 2 | April 23 | April 17 | April 3 | October 23 | October 8 |
| 28°F (hard freeze) | April 19 | April 8 | April 3 | March 20 | November 2 | October 18 |
| 24°F | April 5 | March 30 | March 24 | March 9 | November 17 | October 31 |
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.