ZIP 01453 Zone 6a

Massachusetts · USDA zone 6a, average annual extreme minimum -10°F to -5°F.

Nearest qualified station: FITCHBURG MUNI AP, MA US (USW00004780), 2.2 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 29. Median first 32°F is October 11. The 50% growing-season length is 164 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 19Earlier date. A last 32°F on or after this day is common.
50%April 29Median.
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 1Earlier date. A first 32°F on or before this day is uncommon.
50%October 11Median.
90%October 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%183
50%164
90%147

28°F threshold

10%50%90%
Last, on or afterApril 29April 16April 4
First, on or beforeOctober 9October 23November 5
Season at least206 days188 days170 days

36°F threshold

10%50%90%
Last, on or afterMay 24May 9April 29
First, on or beforeSeptember 20October 1October 13
Season at least160 days144 days126 days

Station FITCHBURG MUNI AP, MA US (USW00004780). Completeness flag R, 22 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 106.1 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