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 06604
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 06604 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Bridgeport, CT, is 4 miles from the ZIP's center: its last spring frost comes after April 5 in half of years and after April 17 in one year in ten. By the USDA's method its plant hardiness zone is 7a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Bridgeport, CTIgor I Sikorsky Memorial Airport | 4 mi | 5 ft | April 5 | April 17 | November 6 | 7a |
| Setauket, NYSetauket Strong | 15 mi | 40 ft | April 15 | May 4 | November 10 | – |
| Ansonia, CT1 mi NE | 15 mi | 136 ft | April 25 | May 10 | October 17 | – |
| Stamford, CT5 mi N | 18 mi | 190 ft | April 17 | May 2 | October 23 | 6b |
| Mount Sinai, NY | 18 mi | 50 ft | April 4 | April 19 | November 7 | – |
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 Bridgeport
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 29 | April 21 | April 16 | April 6 | October 26 | October 11 |
| 32°F | April 17 | April 9 | April 5 | March 25 | November 6 | October 25 |
| 28°F (hard freeze) | April 6 | March 31 | March 26 | March 11 | November 19 | November 6 |
| 24°F | March 30 | March 21 | March 15 | February 28 | December 1 | November 15 |
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.