Alden climate

Alden Frost Dates and Growing Season

NOAA 1991-2020 normals for Wales, 19.5 km from Alden, elevation 1135 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wales. 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 7 and the first fall freeze around October 10, a growing season of about 155 days.

Median at 36°F
last May 20, first September 29
Median at 32°F
last May 7, first October 10
Median at 28°F
last April 28, first October 24

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 1May 28May 25May 22May 20May 17May 14May 10May 5
32°FMay 23May 17May 14May 10May 7May 4May 1Apr 29Apr 25
28°FMay 13May 7May 4Apr 30Apr 28Apr 24Apr 21Apr 18Apr 14
24°FApr 29Apr 24Apr 20Apr 17Apr 15Apr 12Apr 9Apr 6Apr 2
20°FApr 17Apr 13Apr 9Apr 6Apr 4Apr 2Mar 31Mar 29Mar 21
16°FApr 7Apr 3Apr 1Mar 31Mar 28Mar 24Mar 20Mar 17Mar 13

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 17Sep 20Sep 24Sep 26Sep 29Oct 1Oct 4Oct 7Oct 12
32°FSep 27Oct 1Oct 4Oct 7Oct 10Oct 13Oct 17Oct 20Oct 26
28°FOct 7Oct 13Oct 18Oct 21Oct 24Oct 28Nov 1Nov 4Nov 9
24°FOct 22Oct 28Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 21
20°FNov 4Nov 7Nov 11Nov 15Nov 18Nov 21Nov 25Nov 29Dec 4
16°FNov 10Nov 17Nov 21Nov 24Nov 28Dec 1Dec 4Dec 8Dec 15

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°F152145140136132128124119113
32°F175168163159155151147142135
28°F200193188184179174169163156
24°F225218212208204200195190184
20°F248241235231226223219214208
16°F269261255250246241236232225

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
7,096
Cooling degree days, base 65°F
393
Growing degree days, base 40°F
4,271
Growing degree days, base 45°F
3,207
Growing degree days, base 50°F
2,287
Growing degree days, base 55°F
1,502
Growing degree days, base 60°F
858

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28802
February1,14401
March1,026012
April627357
May31525222
June9376436
July30134569
August43108530
September17342329
October4815107
November777021
December1,10003

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 19.5 km from Alden. 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 USC00308910 (Wales). Public domain.