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 49440
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 49440 in zone 6b (the coldest night of a typical year: -5 to 0°F).
The nearest station, Muskegon, MI, is 5 miles from the ZIP's center: its last spring frost comes after April 30 in half of years and after May 18 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 |
|---|---|---|---|---|---|---|
| Muskegon, MIMuskegon County Airport | 5 mi | 625 ft | April 30 | May 18 | October 19 | 6b |
| Grand Haven, MIGrand Haven Wastewater Treatment Plant | 12 mi | 605 ft | April 30 | May 16 | October 24 | – |
| Montague, MI4 mi NW | 18 mi | 650 ft | May 19 | June 6 | October 4 | 6a |
| Fremont, MI4 mi WSW | 18 mi | 800 ft | May 8 | May 25 | October 11 | 6a |
| Kent City, MI2 mi SW | 24 mi | 840 ft | May 14 | May 31 | September 29 | – |
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 Muskegon
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 27 | May 18 | May 12 | April 28 | October 6 | September 24 |
| 32°F | May 18 | May 7 | April 30 | April 17 | October 19 | October 2 |
| 28°F (hard freeze) | May 7 | April 25 | April 19 | April 4 | November 2 | October 17 |
| 24°F | April 21 | April 11 | April 5 | March 22 | November 19 | November 2 |
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.