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 37813
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 37813 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Morristown, TN, is 5 miles from the ZIP's center: its last spring frost comes after April 10 in half of years and after April 26 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Morristown, TNMorristown Radio WCRK | 5 mi | 1,344 ft | April 10 | April 26 | October 28 | – |
| Morristown Weather Office, TN | 8 mi | 1,320 ft | March 31 | April 18 | November 4 | 7b |
| Jefferson City, TN | 13 mi | 1,108 ft | April 24 | May 13 | October 17 | – |
| Newport, TN1 mi NW | 14 mi | 1,036 ft | April 7 | April 23 | October 29 | 7b |
| Rogersville, TN1 mi NE | 23 mi | 1,355 ft | April 14 | May 3 | October 24 | 7b |
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 Morristown
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 8 | April 30 | April 22 | April 5 | October 20 | October 9 |
| 32°F | April 26 | April 16 | April 10 | March 25 | October 28 | October 16 |
| 28°F (hard freeze) | April 14 | April 4 | March 29 | March 11 | November 6 | October 26 |
| 24°F | April 2 | March 24 | March 16 | February 24 | November 19 | November 5 |
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.