ZIP 02170 Zone 7a

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

Nearest qualified station: HINGHAM, MA US (USC00193624), 5.9 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is April 25. Median first 32°F is October 22. 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 13Earlier date. A last 32°F on or after this day is common.
50%April 25Median.
10%May 8Later 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 6Earlier date. A first 32°F on or before this day is uncommon.
50%October 22Median.
90%November 5Later 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%197
50%177
90%158

28°F threshold

10%50%90%
Last, on or afterApril 24April 10March 29
First, on or beforeOctober 19November 2November 16
Season at least224 days205 days185 days

36°F threshold

10%50%90%
Last, on or afterMay 20May 6April 26
First, on or beforeSeptember 28October 9October 24
Season at least172 days154 days136 days

Station HINGHAM, MA US (USC00193624). Completeness flag S, 30 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 10.7 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