ZIP 17401 Zone 7a

Pennsylvania · USDA zone 7a, average annual extreme minimum 0°F to 5°F.

Nearest qualified station: YORK 3 SSW PUMP STN, PA US (USC00369933), 3 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 26. Median first 32°F is October 19. The 50% growing-season length is 177 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%April 7Earlier date. A last 32°F on or after this day is common.
50%April 26Median.
10%May 13Later 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 5Earlier date. A first 32°F on or before this day is uncommon.
50%October 19Median.
90%November 1Later 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%200
50%177
90%155

28°F threshold

10%50%90%
Last, on or afterApril 26April 8March 24
First, on or beforeOctober 15October 31November 13
Season at least225 days203 days182 days

36°F threshold

10%50%90%
Last, on or afterMay 24May 8April 23
First, on or beforeSeptember 25October 8October 22
Season at least175 days153 days133 days

Station YORK 3 SSW PUMP STN, PA US (USC00369933). Completeness flag R, 21 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 · Pennsylvania cities