ZIP 28601 Zone 8a

North Carolina · USDA zone 8a, average annual extreme minimum 10°F to 15°F.

Nearest qualified station: HICKORY FAA AP, NC US (USW00003810), 3.7 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is March 31. Median first 32°F is November 4. The 50% growing-season length is 219 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

ProbabilityDateHow to read it
90%March 13Earlier date. A last 32°F on or after this day is common.
50%March 31Median.
10%April 16Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

ProbabilityDateHow to read it
10%October 22Earlier date. A first 32°F on or before this day is uncommon.
50%November 4Median.
90%November 18Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this longDays
10%241
50%219
90%198

28°F threshold

10%50%90%
Last, on or afterApril 3March 18February 26
First, on or beforeNovember 1November 15December 5
Season at least269 days242 days221 days

36°F threshold

10%50%90%
Last, on or afterApril 29April 13March 29
First, on or beforeOctober 13October 26November 6
Season at least215 days196 days175 days

Station HICKORY FAA AP, NC US (USW00003810). Completeness flag S, 29 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 348.4 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · North Carolina cities