Assumption climate

Assumption Frost Dates and Growing Season

NOAA 1991-2020 normals for Pana, 17.1 km from Assumption, elevation 650 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pana. 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 17 and the first fall freeze around October 23, a growing season of about 188 days.

Median at 36°F
last April 28, first October 12
Median at 32°F
last April 17, first October 23
Median at 28°F
last April 5, 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 14May 7May 3Apr 30Apr 28Apr 25Apr 22Apr 19Apr 15
32°FMay 3Apr 28Apr 24Apr 21Apr 17Apr 13Apr 10Apr 7Apr 4
28°FApr 21Apr 15Apr 11Apr 8Apr 5Apr 3Mar 31Mar 27Mar 20
24°FApr 10Apr 4Apr 1Mar 30Mar 27Mar 22Mar 18Mar 13Mar 7
20°FMar 31Mar 26Mar 22Mar 18Mar 14Mar 11Mar 7Mar 3Feb 25
16°FMar 23Mar 16Mar 12Mar 8Mar 5Mar 2Feb 27Feb 21Feb 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 26Oct 1Oct 5Oct 9Oct 12Oct 15Oct 18Oct 21Oct 24
32°FOct 8Oct 14Oct 17Oct 20Oct 23Oct 25Oct 28Oct 31Nov 3
28°FOct 19Oct 24Oct 28Oct 31Nov 1Nov 4Nov 8Nov 12Nov 17
24°FOct 31Nov 4Nov 7Nov 11Nov 13Nov 17Nov 21Nov 24Dec 1
20°FNov 7Nov 13Nov 17Nov 21Nov 24Nov 28Dec 2Dec 6Dec 13
16°FNov 15Nov 22Nov 27Dec 1Dec 4Dec 8Dec 13Dec 18Dec 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°F186179173169165161157150143
32°F208201196192188183179173165
28°F232223218214210206201195188
24°F258249242238233228222217210
20°F279270264259254248243237230
16°F299291284279274268263256248

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
5,289
Cooling degree days, base 65°F
1,172
Growing degree days, base 40°F
6,120
Growing degree days, base 45°F
4,868
Growing degree days, base 50°F
3,750
Growing degree days, base 55°F
2,760
Growing degree days, base 60°F
1,900

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14802
February92306
March713249
April35912175
May12490435
June12253691
July1348812
August3298759
September58142536
October30626230
November653249
December98906

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 17.1 km from Assumption. 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 USC00116579 (Pana). Public domain.