ZIP 27539 Zone 8a

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

Nearest qualified station: CARY, NC US (USC00311535), 3.3 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is March 31. Median first 32°F is November 10. The 50% growing-season length is 226 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 12Earlier date. A last 32°F on or after this day is common.
50%March 31Median.
10%April 12Later 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 30Earlier date. A first 32°F on or before this day is uncommon.
50%November 10Median.
90%November 27Later 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%251
50%226
90%208

28°F threshold

10%50%90%
Last, on or afterApril 2March 17February 27
First, on or beforeNovember 7November 24December 17
Season at least283 days254 days228 days

36°F threshold

10%50%90%
Last, on or afterApril 23April 10March 26
First, on or beforeOctober 18October 31November 13
Season at least225 days203 days185 days

Station CARY, NC US (USC00311535). Completeness flag R, 20 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 118.9 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