New Union climate

New Union Frost Dates and Growing Season

NOAA 1991-2020 normals for Manchester #2, 2 km from New Union, elevation 1070 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Manchester #2. 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 13 and the first fall freeze around October 24, a growing season of about 192 days.

Median at 36°F
last April 26, first October 15
Median at 32°F
last April 13, first October 24
Median at 28°F
last April 1, first November 1

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 11May 5May 2Apr 30Apr 26Apr 23Apr 20Apr 16Apr 11
32°FApr 30Apr 25Apr 21Apr 17Apr 13Apr 10Apr 6Apr 2Mar 27
28°FApr 18Apr 11Apr 7Apr 3Apr 1Mar 29Mar 25Mar 20Mar 13
24°FApr 5Apr 1Mar 27Mar 22Mar 19Mar 15Mar 10Mar 5Feb 28
20°FMar 27Mar 19Mar 14Mar 8Mar 3Feb 28Feb 24Feb 17Feb 7
16°FMar 14Mar 4Feb 28Feb 23Feb 17Feb 11Feb 5Jan 31Jan 22

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 4Oct 7Oct 10Oct 12Oct 15Oct 18Oct 20Oct 23Oct 27
32°FOct 11Oct 16Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 5
28°FOct 19Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 15
24°FOct 28Nov 1Nov 4Nov 8Nov 11Nov 14Nov 19Nov 24Dec 2
20°FNov 8Nov 13Nov 17Nov 21Nov 25Dec 1Dec 5Dec 11Dec 23
16°FNov 18Nov 26Dec 1Dec 5Dec 11Dec 19Dec 29Jan 3Jan 13

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°F192185180175172168164159151
32°F213206201197192189184179172
28°F238229223218214210206200192
24°F265255248243237232227221213
20°F300289281272266259254247236
16°F332321313306299292285276266

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
99% 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
4,137
Cooling degree days, base 65°F
1,129
Growing degree days, base 40°F
6,643
Growing degree days, base 45°F
5,222
Growing degree days, base 50°F
3,959
Growing degree days, base 55°F
2,863
Growing degree days, base 60°F
1,919

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January873021
February702024
March547387
April28618226
May9781453
June6222666
July0337801
August2299762
September41143553
October25524267
November553268
December775031

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 km from New Union. 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 USC00405595 (Manchester #2). Public domain.