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 49509
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 49509 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, East Grand Rapids, MI, is 5 miles from the ZIP's center: its last spring frost comes after May 6 in half of years and after May 23 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| East Grand Rapids, MI | 5 mi | 746 ft | May 6 | May 23 | October 10 | – |
| Grand Rapids, MIGrand Rapids Gerald R Ford International Airport | 8 mi | 778 ft | April 29 | May 15 | October 20 | 6a |
| Kentwood, MIWeather Office Grand Rapids | 8 mi | 775 ft | April 30 | May 17 | October 14 | – |
| Kent City, MI2 mi SW | 21 mi | 840 ft | May 14 | May 31 | September 29 | – |
| Allegan, MI5 mi NE | 22 mi | 750 ft | May 4 | May 22 | October 15 | – |
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 East 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 31 | May 24 | May 18 | May 3 | October 1 | September 20 |
| 32°F | May 23 | May 14 | May 6 | April 24 | October 10 | September 29 |
| 28°F (hard freeze) | May 13 | May 2 | April 27 | April 11 | October 23 | October 8 |
| 24°F | May 1 | April 21 | April 15 | March 31 | November 5 | October 21 |
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.