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 49546
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 49546 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Grand Rapids, MI, is 3 miles from the ZIP's center: its last spring frost comes after April 29 in half of years and after May 15 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 |
|---|---|---|---|---|---|---|
| Grand Rapids, MIGrand Rapids Gerald R Ford International Airport | 3 mi | 778 ft | April 29 | May 15 | October 20 | 6a |
| Kentwood, MIWeather Office Grand Rapids | 3 mi | 775 ft | April 30 | May 17 | October 14 | – |
| East Grand Rapids, MI | 4 mi | 746 ft | May 6 | May 23 | October 10 | – |
| Kent City, MI2 mi SW | 22 mi | 840 ft | May 14 | May 31 | September 29 | – |
| Ionia, MI2 mi SSW | 23 mi | 805 ft | May 3 | May 21 | October 12 | 6a |
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 Grand Rapids
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 15 | May 7 | April 24 | October 7 | September 26 |
| 32°F | May 15 | May 4 | April 29 | April 14 | October 20 | October 4 |
| 28°F (hard freeze) | May 2 | April 22 | April 16 | April 2 | November 2 | October 19 |
| 24°F | April 19 | April 9 | April 4 | March 20 | November 15 | November 1 |
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.