Magoffin County climate

Magoffin County Frost Dates and Growing Season

NOAA 1991-2020 normals for Salyersville Wtr Wks, 3.6 km from Magoffin County, elevation 970 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Salyersville Wtr Wks. 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 25 and the first fall freeze around October 21, a growing season of about 179 days.

Median at 36°F
last May 3, first October 12
Median at 32°F
last April 25, first October 21
Median at 28°F
last April 11, first October 31

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 21May 14May 10May 6May 3Apr 30Apr 28Apr 24Apr 19
32°FMay 11May 5May 1Apr 28Apr 25Apr 21Apr 18Apr 15Apr 9
28°FApr 30Apr 23Apr 19Apr 15Apr 11Apr 7Apr 4Apr 1Mar 28
24°FApr 14Apr 8Apr 4Apr 1Mar 31Mar 27Mar 22Mar 18Mar 11
20°FApr 3Mar 30Mar 25Mar 21Mar 17Mar 13Mar 8Mar 2Feb 24
16°FMar 22Mar 16Mar 12Mar 7Mar 2Feb 27Feb 21Feb 12Feb 4

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 4Oct 7Oct 10Oct 12Oct 14Oct 17Oct 20Oct 24
32°FOct 10Oct 13Oct 16Oct 19Oct 21Oct 24Oct 26Oct 30Nov 1
28°FOct 17Oct 21Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 11
24°FOct 27Nov 1Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 25
20°FNov 5Nov 10Nov 13Nov 16Nov 19Nov 24Nov 28Dec 3Dec 13
16°FNov 14Nov 20Nov 25Nov 30Dec 5Dec 11Dec 19Dec 25Jan 2

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°F178173169165162158154149142
32°F198191186183179175171166160
28°F221215209205201197192187179
24°F249240235230225221217211204
20°F277267260255249245240234226
16°F310300292286279273265259247

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
4,722
Cooling degree days, base 65°F
988
Growing degree days, base 40°F
6,070
Growing degree days, base 45°F
4,731
Growing degree days, base 50°F
3,565
Growing degree days, base 55°F
2,568
Growing degree days, base 60°F
1,717

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98604
February79405
March658034
April35814174
May11164422
June7190633
July0308773
August1261725
September54131528
October30019219
November603042
December85107

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 3.6 km from Magoffin County. 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 USC00157130 (Salyersville Wtr Wks). Public domain.