ZIP 02451 Zone 6b

Massachusetts · USDA zone 6b, average annual extreme minimum -5°F to 0°F.

Nearest qualified station: BEDFORD HANSCOM FLD, MA US (USW00014702), 5.1 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 28. Median first 32°F is October 10. The 50% growing-season length is 165 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 13Earlier date. A last 32°F on or after this day is common.
50%April 28Median.
10%May 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%September 28Earlier date. A first 32°F on or before this day is uncommon.
50%October 10Median.
90%October 28Later 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%186
50%165
90%146

28°F threshold

10%50%90%
Last, on or afterApril 29April 12April 1
First, on or beforeOctober 7October 25November 8
Season at least214 days194 days171 days

36°F threshold

10%50%90%
Last, on or afterMay 23May 10April 28
First, on or beforeSeptember 17October 1October 13
Season at least160 days143 days125 days

Station BEDFORD HANSCOM FLD, MA US (USW00014702). 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 40.5 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Massachusetts cities