ZIP 05401 Zone 5b

Vermont · USDA zone 5b, average annual extreme minimum -15°F to -10°F.

Nearest qualified station: BURLINGTON INTL AP, VT US (USW00014742), 3.4 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 29. Median first 32°F is October 15. The 50% growing-season length is 169 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 17Earlier date. A last 32°F on or after this day is common.
50%April 29Median.
10%May 11Later 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 2Earlier date. A first 32°F on or before this day is uncommon.
50%October 15Median.
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%187
50%169
90%149

28°F threshold

10%50%90%
Last, on or afterApril 30April 18April 5
First, on or beforeOctober 12October 28November 12
Season at least211 days193 days173 days

36°F threshold

10%50%90%
Last, on or afterMay 23May 8April 27
First, on or beforeSeptember 23October 4October 19
Season at least166 days147 days129 days

Station BURLINGTON INTL AP, VT US (USW00014742). 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 100.6 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Vermont cities