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 48602
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 48602 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Saginaw #3, MI, is 1 miles from the ZIP's center: its last spring frost comes after April 29 in half of years and after May 13 in one year in ten. By the USDA's method its plant hardiness zone is 6a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Saginaw #3, MI | 1 mi | 600 ft | April 29 | May 13 | October 21 | 6a |
| Saginaw, MISaginaw Mbs International Airport | 9 mi | 660 ft | April 26 | May 13 | October 17 | 6a |
| Auburn, MI2 mi NE | 14 mi | 605 ft | May 3 | May 23 | October 14 | – |
| Frankenmuth, MI1 mi SE | 15 mi | 635 ft | May 3 | May 20 | October 12 | – |
| Essexville, MI | 15 mi | 588 ft | April 27 | May 11 | October 20 | – |
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 Saginaw #3
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 23 | May 14 | May 7 | April 26 | October 9 | September 27 |
| 32°F | May 13 | May 4 | April 29 | April 14 | October 21 | October 5 |
| 28°F (hard freeze) | May 1 | April 23 | April 17 | April 2 | November 3 | October 20 |
| 24°F | April 19 | April 11 | April 5 | March 22 | November 14 | November 3 |
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.