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 89431
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 89431 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Sparks, NV, is 1 miles from the ZIP's center: its last spring frost comes after May 1 in half of years and after May 25 in one year in ten. By the USDA's method its plant hardiness zone is 7b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Sparks, NV | 1 mi | 4,357 ft | May 1 | May 25 | October 10 | 7b |
| Reno Weather Office, NV | 3 mi | 4,987 ft | April 28 | May 19 | October 27 | 7b |
| Reno, NVReno Airport | 4 mi | 4,410 ft | April 20 | May 5 | October 23 | 7b |
| Spanish Springs, NV | 7 mi | 4,489 ft | May 3 | May 24 | October 10 | – |
| Stead, NV | 9 mi | 5,101 ft | May 8 | June 2 | October 12 | – |
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 Sparks
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) | June 9 | May 31 | May 23 | May 4 | October 1 | September 16 |
| 32°F | May 25 | May 8 | May 1 | April 17 | October 10 | September 29 |
| 28°F (hard freeze) | May 2 | April 23 | April 16 | March 30 | October 23 | October 7 |
| 24°F | April 18 | April 6 | March 27 | March 3 | November 4 | October 20 |
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.