ZIP 20175 Zone 7b

Virginia · USDA zone 7b, average annual extreme minimum 5°F to 10°F.

Nearest qualified station: PURCELLVILLE, VA US (USC00444909), 7.8 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 16. Median first 32°F is October 25. The 50% growing-season length is 189 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 31Earlier date. A last 32°F on or after this day is common.
50%April 16Median.
10%May 7Later 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 7Earlier date. A first 32°F on or before this day is uncommon.
50%October 25Median.
90%November 7Later 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%210
50%189
90%165

28°F threshold

10%50%90%
Last, on or afterApril 17April 2March 20
First, on or beforeOctober 21November 5November 20
Season at least236 days215 days194 days

36°F threshold

10%50%90%
Last, on or afterMay 20May 1April 14
First, on or beforeSeptember 29October 12October 27
Season at least188 days165 days141 days

Station PURCELLVILLE, VA US (USC00444909). 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 155.4 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Virginia cities