Berne climate

Berne Frost Dates and Growing Season

NOAA 1991-2020 normals for Berne Wwtp, 2.2 km from Berne, elevation 839 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Berne 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 April 23 and the first fall freeze around October 22, a growing season of about 181 days.

Median at 36°F
last May 1, first October 11
Median at 32°F
last April 23, first October 22
Median at 28°F
last April 13, first November 2

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 16May 10May 6May 3May 1Apr 29Apr 27Apr 23Apr 19
32°FMay 7May 2Apr 30Apr 27Apr 23Apr 21Apr 18Apr 15Apr 9
28°FApr 29Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31
24°FApr 16Apr 11Apr 6Apr 4Apr 2Mar 31Mar 28Mar 23Mar 17
20°FApr 6Apr 1Mar 30Mar 27Mar 23Mar 20Mar 17Mar 12Mar 7
16°FMar 30Mar 25Mar 20Mar 17Mar 14Mar 10Mar 7Mar 3Feb 26

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 27Oct 2Oct 5Oct 8Oct 11Oct 13Oct 16Oct 20Oct 24
32°FOct 9Oct 14Oct 17Oct 20Oct 22Oct 25Oct 29Oct 31Nov 4
28°FOct 20Oct 24Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 17
24°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 21Nov 26Dec 2
20°FNov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 2Dec 7Dec 14
16°FNov 16Nov 23Nov 27Dec 1Dec 5Dec 9Dec 14Dec 19Dec 26

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°F180173169164160157153148141
32°F201194190185181177173170162
28°F223216211207204199195190182
24°F247240233228224220217212206
20°F271263256251246241236231224
16°F292284276271266262256251243

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
6,034
Cooling degree days, base 65°F
877
Growing degree days, base 40°F
5,423
Growing degree days, base 45°F
4,253
Growing degree days, base 50°F
3,216
Growing degree days, base 55°F
2,304
Growing degree days, base 60°F
1,523

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,22902
February1,03303
March844127
April4667114
May18065361
June24195621
July3279741
August8217674
September8998461
October37414176
November720031
December1,06305

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 2.2 km from Berne. 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 USC00120676 (Berne Wwtp). Public domain.