Frankfort climate

Frankfort Frost Dates and Growing Season

NOAA 1991-2020 normals for Frankfort 6NE, 9.6 km from Frankfort, elevation 1264 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Frankfort 6NE. 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 20 and the first fall freeze around October 18, a growing season of about 180 days.

Median at 36°F
last April 30, first October 8
Median at 32°F
last April 20, first October 18
Median at 28°F
last April 7, first October 28

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 7May 4May 2Apr 30Apr 27Apr 24Apr 20Apr 15
32°FMay 3Apr 30Apr 26Apr 23Apr 20Apr 17Apr 13Apr 10Apr 4
28°FApr 24Apr 19Apr 14Apr 10Apr 7Apr 4Apr 2Mar 29Mar 23
24°FApr 15Apr 9Apr 5Apr 2Mar 31Mar 27Mar 22Mar 18Mar 11
20°FApr 4Mar 31Mar 26Mar 22Mar 19Mar 15Mar 10Mar 6Mar 2
16°FMar 24Mar 18Mar 15Mar 11Mar 7Mar 4Mar 1Feb 25Feb 19

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 25Sep 29Oct 2Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21
32°FOct 1Oct 8Oct 12Oct 15Oct 18Oct 21Oct 23Oct 26Oct 30
28°FOct 13Oct 19Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 10
24°FOct 23Oct 28Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 24
20°FNov 1Nov 5Nov 9Nov 12Nov 16Nov 20Nov 24Nov 28Dec 4
16°FNov 7Nov 14Nov 18Nov 24Nov 28Dec 1Dec 5Dec 10Dec 17

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°F180173168164160157152148141
32°F201194189185180176172167159
28°F223214209205201198194189180
24°F245236231226221216212206200
20°F267257252246241237231225217
16°F289279272266262256252244235

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
5,808
Cooling degree days, base 65°F
1,094
Growing degree days, base 40°F
5,772
Growing degree days, base 45°F
4,580
Growing degree days, base 50°F
3,511
Growing degree days, base 55°F
2,585
Growing degree days, base 60°F
1,775

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,21500
February97005
March752130
April4156140
May15068393
June9225665
July2356819
August5296756
September90124486
October36718187
November742128
December1,09201

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 9.6 km from Frankfort. 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 USC00142881 (Frankfort 6NE). Public domain.