Appleton climate

Appleton Frost Dates and Growing Season

NOAA 1991-2020 normals for Milan 1NW, 11.1 km from Appleton, elevation 1020 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Milan 1NW. 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 3 and the first fall freeze around October 2, a growing season of about 151 days.

Median at 36°F
last May 12, first September 24
Median at 32°F
last May 3, first October 2
Median at 28°F
last April 23, first October 12

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 23May 18May 15May 12May 10May 7May 3Apr 30
32°FMay 17May 12May 9May 5May 3Apr 30Apr 28Apr 25Apr 20
28°FMay 9May 3Apr 30Apr 27Apr 23Apr 21Apr 17Apr 13Apr 8
24°FMay 1Apr 25Apr 21Apr 17Apr 14Apr 11Apr 7Apr 4Mar 31
20°FApr 22Apr 16Apr 12Apr 8Apr 5Apr 3Mar 31Mar 27Mar 20
16°FApr 13Apr 7Apr 3Apr 1Mar 29Mar 25Mar 21Mar 17Mar 12

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 10Sep 14Sep 18Sep 21Sep 24Sep 26Sep 29Oct 2Oct 5
32°FSep 18Sep 23Sep 27Sep 30Oct 2Oct 4Oct 7Oct 10Oct 15
28°FSep 28Oct 2Oct 5Oct 9Oct 12Oct 15Oct 19Oct 22Oct 25
24°FOct 7Oct 12Oct 17Oct 21Oct 23Oct 26Oct 29Nov 1Nov 6
20°FOct 18Oct 24Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 16
16°FOct 28Nov 1Nov 4Nov 7Nov 10Nov 12Nov 15Nov 19Nov 24

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°F151145140136132128124119112
32°F170162158154151147143138131
28°F191183179174170165161156150
24°F212205199194189185181175168
20°F229222218212209204200194186
16°F247240234229225221216211202

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
7,687
Cooling degree days, base 65°F
764
Growing degree days, base 40°F
4,868
Growing degree days, base 45°F
3,827
Growing degree days, base 50°F
2,889
Growing degree days, base 55°F
2,058
Growing degree days, base 60°F
1,347

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,57600
February1,29400
March1,020011
April553481
May21153327
June32173591
July7257714
August19191637
September13579402
October5008116
November945011
December1,39600

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 11.1 km from Appleton. 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 USC00215400 (Milan 1NW). Public domain.