Millersburg climate

Millersburg Frost Dates and Growing Season

NOAA 1991-2020 normals for Cynthiana, 16 km from Millersburg, elevation 700 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cynthiana. 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 18 and the first fall freeze around October 23, a growing season of about 188 days.

Median at 36°F
last April 29, first October 14
Median at 32°F
last April 18, first October 23
Median at 28°F
last April 5, first November 2

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 15May 9May 5May 1Apr 29Apr 26Apr 23Apr 19Apr 14
32°FMay 5Apr 30Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8Apr 2
28°FApr 23Apr 18Apr 14Apr 9Apr 5Apr 2Mar 30Mar 26Mar 20
24°FApr 10Apr 3Mar 31Mar 28Mar 24Mar 21Mar 17Mar 12Mar 6
20°FApr 1Mar 25Mar 21Mar 17Mar 13Mar 10Mar 6Feb 28Feb 21
16°FMar 21Mar 14Mar 9Mar 6Mar 2Feb 26Feb 19Feb 11Feb 3

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

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°F185180175172168164161156149
32°F208201196192188184180175167
28°F232225220215211207203198190
24°F260249243238233229224218211
20°F285276268262257251246240232
16°F315304296290283276269263252

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
4,827
Cooling degree days, base 65°F
1,124
Growing degree days, base 40°F
6,240
Growing degree days, base 45°F
4,927
Growing degree days, base 50°F
3,758
Growing degree days, base 55°F
2,734
Growing degree days, base 60°F
1,856

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,02409
February829010
March660156
April33312191
May11787439
June15226661
July0340804
August2300762
September52137536
October29320229
November620049
December882013

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 16 km from Millersburg. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00151998 (Cynthiana). Public domain.