Brooklet climate

Brooklet Frost Dates and Growing Season

NOAA 1991-2020 normals for Brooklet 1 W, 1.1 km from Brooklet, elevation 180 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brooklet 1 W. 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 7 and the first fall freeze around November 21, a growing season of about 257 days.

Median at 36°F
last March 22, first November 9
Median at 32°F
last March 7, first November 21
Median at 28°F
last February 22, first December 8

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 10Apr 3Mar 30Mar 26Mar 22Mar 18Mar 15Mar 9Mar 2
32°FMar 27Mar 20Mar 16Mar 12Mar 7Mar 3Feb 28Feb 21Feb 11
28°FMar 17Mar 10Mar 4Feb 28Feb 22Feb 16Feb 10Feb 2Jan 25
24°FMar 6Feb 27Feb 19Feb 11Feb 4Jan 31Jan 24Jan 14Jan 2
20°FFeb 28Feb 14Feb 7Feb 1Jan 25Jan 18Jan 11Jan 3Dec 28
16°FFeb 16Feb 12Feb 7Feb 3Jan 31Jan 20Jan 18Jan 12Jan 6

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°FOct 28Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 20Nov 26
32°FNov 5Nov 10Nov 14Nov 18Nov 21Nov 25Nov 30Dec 5Dec 15
28°FNov 16Nov 22Nov 28Dec 4Dec 8Dec 15Dec 23Jan 1Jan 9
24°FDec 2Dec 9Dec 17Dec 26Jan 1Jan 5Jan 11Jan 20Feb 3
20°FDec 16Dec 25Jan 1Jan 7Jan 11Jan 17Jan 26Feb 3Feb 14
16°FJan 5Jan 9Jan 16Jan 18Jan 23Feb 1Feb 6Feb 12Feb 16

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°F256247241235230226221215207
32°F288277268262257250245240231
28°F326313304297290282275267257
24°F365351339332324315306299285
20°F365365365365360349337329312
16°F365365365365365365365365340

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
90% of years
20°F or colder
53% of years
16°F or colder
15% 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
1,913
Cooling degree days, base 65°F
2,412
Growing degree days, base 40°F
9,671
Growing degree days, base 45°F
7,941
Growing degree days, base 50°F
6,322
Growing degree days, base 55°F
4,852
Growing degree days, base 60°F
3,541

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4974104
February3635131
March23028289
April7696472
May10279735
June0447897
July0533998
August0505970
September2348796
October58133542
November24926251
December4297136

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 1.1 km from Brooklet. 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 USC00091266 (Brooklet 1 W). Public domain.