New Bethlehem climate

New Bethlehem Frost Dates and Growing Season

NOAA 1991-2020 normals for Putneyville 2 Se Dam, 9.5 km from New Bethlehem, elevation 1280 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Putneyville 2 Se Dam. 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 10 and the first fall freeze around October 12, a growing season of about 155 days.

Median at 36°F
last May 21, first October 1
Median at 32°F
last May 10, first October 12
Median at 28°F
last April 28, first October 26

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 4Jun 1May 28May 25May 21May 18May 13May 8May 2
32°FMay 28May 23May 19May 14May 10May 7May 2Apr 29Apr 24
28°FMay 19May 12May 7May 2Apr 28Apr 26Apr 22Apr 19Apr 15
24°FMay 7Apr 30Apr 23Apr 19Apr 16Apr 13Apr 9Apr 6Apr 1
20°FApr 18Apr 14Apr 9Apr 6Apr 3Apr 1Mar 29Mar 25Mar 19
16°FApr 6Apr 1Mar 30Mar 27Mar 23Mar 19Mar 16Mar 12Mar 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°FSep 18Sep 23Sep 27Sep 30Oct 1Oct 4Oct 6Oct 9Oct 14
32°FSep 30Oct 3Oct 6Oct 8Oct 12Oct 15Oct 19Oct 22Oct 27
28°FOct 10Oct 16Oct 19Oct 22Oct 26Oct 29Nov 1Nov 4Nov 8
24°FOct 22Oct 28Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 20
20°FNov 4Nov 8Nov 12Nov 15Nov 18Nov 21Nov 26Dec 1Dec 5
16°FNov 12Nov 18Nov 24Nov 28Dec 1Dec 3Dec 8Dec 13Dec 21

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°F156148143137133128124119112
32°F177170164160155150144139131
28°F199192187182178174168162154
24°F225218212207203198193187178
20°F253245239234230225220214206
16°F278269264259254249243238231

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
6,421
Cooling degree days, base 65°F
515
Growing degree days, base 40°F
4,708
Growing degree days, base 45°F
3,581
Growing degree days, base 50°F
2,597
Growing degree days, base 55°F
1,752
Growing degree days, base 60°F
1,050

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,21502
February1,04702
March910018
April519388
May24831273
June63102490
July15174625
August24148589
September13851368
October4486119
November749019
December1,04604

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 9.5 km from New Bethlehem. 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 USC00367229 (Putneyville 2 Se Dam). Public domain.