Berlin climate

Berlin Frost Dates and Growing Season

NOAA 1991-2020 normals for Berlin Wwtp, 2.5 km from Berlin, elevation 766 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Berlin Wwtp. 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 1 and the first fall freeze around October 8, a growing season of about 158 days.

Median at 36°F
last May 12, first September 28
Median at 32°F
last May 1, first October 8
Median at 28°F
last April 21, first October 20

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°FMay 27May 22May 19May 15May 12May 9May 6May 3Apr 29
32°FMay 16May 11May 7May 4May 1Apr 29Apr 26Apr 23Apr 19
28°FMay 4Apr 30Apr 26Apr 23Apr 21Apr 18Apr 16Apr 12Apr 7
24°FApr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 4Apr 1Mar 27
20°FApr 16Apr 10Apr 6Apr 4Apr 2Mar 31Mar 28Mar 23Mar 18
16°FApr 6Apr 2Mar 31Mar 28Mar 24Mar 21Mar 18Mar 15Mar 10

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 16Sep 20Sep 23Sep 25Sep 28Sep 30Oct 3Oct 6Oct 11
32°FSep 24Sep 28Oct 1Oct 4Oct 8Oct 11Oct 14Oct 17Oct 22
28°FOct 4Oct 10Oct 14Oct 17Oct 20Oct 23Oct 26Oct 30Nov 3
24°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 14
20°FOct 30Nov 2Nov 5Nov 8Nov 11Nov 13Nov 17Nov 20Nov 26
16°FNov 5Nov 10Nov 13Nov 16Nov 20Nov 23Nov 26Nov 29Dec 4

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°F157151147142138134130126120
32°F176170165162158154150145139
28°F200194189185181177172167161
24°F224217212209205201197192186
20°F243237232227223219215211205
16°F261254249244241237232227221

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
7,737
Cooling degree days, base 65°F
501
Growing degree days, base 40°F
4,315
Growing degree days, base 45°F
3,309
Growing degree days, base 50°F
2,428
Growing degree days, base 55°F
1,658
Growing degree days, base 60°F
1,007

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49200
February1,25400
March1,052111
April636144
May28723236
June58102496
July14186637
August26139578
September17346333
October531487
November91707
December1,29700

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 2.5 km from Berlin. 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 USC00470742 (Berlin Wwtp). Public domain.