Appleton climate

Appleton Frost Dates and Growing Season

NOAA 1991-2020 normals for Appleton, 2.5 km from Appleton, elevation 792 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Appleton. 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 4 and the first fall freeze around October 6, a growing season of about 154 days.

Median at 36°F
last May 15, first September 28
Median at 32°F
last May 4, first October 6
Median at 28°F
last April 23, first October 18

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 29May 25May 22May 19May 15May 11May 8May 5Apr 30
32°FMay 20May 14May 10May 7May 4May 1Apr 29Apr 26Apr 21
28°FMay 8May 4Apr 30Apr 27Apr 23Apr 21Apr 17Apr 14Apr 9
24°FApr 26Apr 21Apr 18Apr 15Apr 12Apr 9Apr 7Apr 4Mar 31
20°FApr 16Apr 11Apr 7Apr 5Apr 3Apr 1Mar 29Mar 24Mar 19
16°FApr 7Apr 2Mar 31Mar 29Mar 26Mar 22Mar 19Mar 16Mar 11

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 15Sep 19Sep 22Sep 25Sep 28Oct 1Oct 3Oct 6Oct 11
32°FSep 23Sep 27Oct 1Oct 4Oct 6Oct 9Oct 12Oct 16Oct 21
28°FOct 1Oct 7Oct 11Oct 15Oct 18Oct 22Oct 26Oct 29Nov 3
24°FOct 14Oct 21Oct 26Oct 29Nov 1Nov 3Nov 6Nov 10Nov 16
20°FOct 29Nov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 20Nov 25
16°FNov 4Nov 10Nov 14Nov 17Nov 20Nov 22Nov 25Nov 29Dec 4

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°F154146142139134130126122116
32°F176168163158154151146141134
28°F198191186181177173169163156
24°F221215211207203199194190183
20°F242235230226222218214210204
16°F260253248244238235231226219

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
7,622
Cooling degree days, base 65°F
588
Growing degree days, base 40°F
4,432
Growing degree days, base 45°F
3,417
Growing degree days, base 50°F
2,525
Growing degree days, base 55°F
1,753
Growing degree days, base 60°F
1,102

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,46600
February1,24900
March1,04409
April633146
May28632245
June65119504
July12211663
August24165606
September16656351
October514492
November88509
December1,27900

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 2.5 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 USC00470265 (Appleton). Public domain.