Gloucester climate

Gloucester Frost Dates and Growing Season

NOAA 1991-2020 normals for Beaufort Michael J Smith Fld, 11 km from Gloucester, elevation 11 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Beaufort Michael J Smith Fld. 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 March 10 and the first fall freeze around December 1, a growing season of about 265 days.

Median at 36°F
last March 21, first November 15
Median at 32°F
last March 10, first December 1
Median at 28°F
last February 23, first December 17

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°FApr 6Apr 1Mar 28Mar 24Mar 21Mar 18Mar 15Mar 12Mar 6
32°FMar 26Mar 20Mar 17Mar 13Mar 10Mar 6Mar 2Feb 26Feb 18
28°FMar 16Mar 9Mar 4Feb 28Feb 23Feb 17Feb 11Feb 5Jan 29
24°FMar 3Feb 23Feb 15Feb 8Feb 2Jan 30Jan 24Jan 17Jan 8
20°FFeb 13Feb 4Jan 31Jan 29Jan 24Jan 19Jan 15Jan 9Jan 1
16°FFeb 14Feb 5Jan 31Jan 30Jan 25Jan 21Jan 18Jan 14Jan 9

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°FNov 1Nov 5Nov 8Nov 12Nov 15Nov 19Nov 24Nov 29Dec 4
32°FNov 10Nov 16Nov 21Nov 26Dec 1Dec 4Dec 8Dec 14Dec 24
28°FNov 25Dec 1Dec 6Dec 12Dec 17Dec 24Dec 30Jan 6Jan 13
24°FDec 9Dec 16Dec 25Dec 31Jan 4Jan 9Jan 14Jan 20Jan 30
20°FDec 21Dec 30Jan 4Jan 9Jan 13Jan 17Jan 21Jan 27Feb 3
16°FJan 7Jan 12Jan 15Jan 18Jan 21Jan 25Jan 29Feb 2Feb 7

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°F264255249243239234230224216
32°F295282276270265259254248240
28°F329318309303296291284277267
24°F365350340334329322314307296
20°F365365365365357348339334324
16°F365365365365365365365357339

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
99% of years
24°F or colder
90% of years
20°F or colder
56% of years
16°F or colder
19% 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
2,378
Cooling degree days, base 65°F
1,977
Growing degree days, base 40°F
8,809
Growing degree days, base 45°F
7,129
Growing degree days, base 50°F
5,580
Growing degree days, base 55°F
4,195
Growing degree days, base 60°F
2,991

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January583070
February472171
March3496171
April13146368
May22180623
June0371820
July0482947
August0450915
September3314762
October78108496
November27116222
December4704114

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 11 km from Gloucester. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00093765 (Beaufort Michael J Smith Fld). Public domain.