Sandwich climate

Sandwich Frost Dates and Growing Season

NOAA 1991-2020 normals for E Sandwich, 5.9 km from Sandwich, elevation 692 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for E Sandwich. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around May 6 and the first fall freeze around October 6, a growing season of about 151 days.

Median at 36°F
last May 19, first September 26
Median at 32°F
last May 6, first October 6
Median at 28°F
last April 24, first October 19

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJun 2May 28May 25May 22May 19May 17May 14May 11May 7
32°FMay 19May 15May 11May 9May 6May 4May 2Apr 29Apr 26
28°FMay 5May 2Apr 30Apr 27Apr 24Apr 22Apr 19Apr 15Apr 10
24°FApr 22Apr 19Apr 16Apr 12Apr 9Apr 7Apr 5Apr 3Mar 31
20°FApr 10Apr 7Apr 5Apr 3Apr 1Mar 31Mar 28Mar 24Mar 18
16°FApr 2Mar 31Mar 30Mar 27Mar 24Mar 21Mar 18Mar 15Mar 11

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 14Sep 17Sep 21Sep 24Sep 26Sep 29Oct 1Oct 4Oct 8
32°FSep 24Sep 29Oct 1Oct 3Oct 6Oct 8Oct 11Oct 14Oct 19
28°FOct 3Oct 8Oct 12Oct 16Oct 19Oct 22Oct 26Oct 31Nov 4
24°FOct 19Oct 24Oct 28Nov 1Nov 2Nov 5Nov 8Nov 12Nov 17
20°FNov 2Nov 6Nov 9Nov 12Nov 15Nov 17Nov 21Nov 24Nov 30
16°FNov 11Nov 16Nov 19Nov 23Nov 26Nov 29Dec 1Dec 4Dec 10

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F145140136132129126122117111
32°F167162158154151148144139133
28°F197191185182177174169163158
24°F222217212209205201198192185
20°F245238233230226223219215209
16°F265258253249245242238233227

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
7,643
Cooling degree days, base 65°F
357
Growing degree days, base 40°F
3,979
Growing degree days, base 45°F
3,003
Growing degree days, base 50°F
2,143
Growing degree days, base 55°F
1,408
Growing degree days, base 60°F
805

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,40600
February1,21100
March1,07100
April668026
May31514194
June8860423
July18148595
August31102536
September19632299
October548161
November873010
December1,21800

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 5.9 km from Sandwich. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00272303 (E Sandwich). Public domain.