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 77303
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 77303 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Conroe, TX, is 3 miles from the ZIP's center: its last spring frost comes after March 11 in half of years and after April 3 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Conroe, TXConroe Montgomery County Airport | 3 mi | 245 ft | March 11 | April 3 | November 19 | 9a |
| Conroe station, TX | 7 mi | 245 ft | February 24 | March 17 | December 2 | 9a |
| Cleveland, TX | 18 mi | 196 ft | March 7 | March 29 | November 20 | 9a |
| Houston Hooks Mem Airport, TX | 24 mi | 152 ft | February 19 | March 15 | December 3 | 9a |
| Huntsville station, TX | 25 mi | 494 ft | March 1 | March 22 | November 28 | 9a |
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 Conroe
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) | April 15 | April 2 | March 24 | March 3 | November 8 | October 24 |
| 32°F | April 3 | March 21 | March 11 | February 14 | November 19 | November 1 |
| 28°F (hard freeze) | March 18 | March 4 | February 21 | January 22 | December 4 | November 11 |
| 24°F | March 8 | February 16 | January 30 | December 28 | January 1 | November 30 |
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.