McKinley County climate

McKinley County Frost Dates and Growing Season

NOAA 1991-2020 normals for Mcgaffey 5 Se, 31.8 km from McKinley County, elevation 8000 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mcgaffey 5 Se. 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 June 5 and the first fall freeze around September 25, a growing season of about 109 days.

Median at 36°F
last June 16, first September 17
Median at 32°F
last June 5, first September 25
Median at 28°F
last May 26, first October 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°FJul 1Jun 27Jun 23Jun 20Jun 16Jun 13Jun 9Jun 6Jun 1
32°FJun 22Jun 16Jun 12Jun 8Jun 5Jun 3May 31May 27May 21
28°FJun 12Jun 6Jun 3May 31May 26May 22May 18May 14May 8
24°FJun 4May 27May 21May 16May 13May 9May 5Apr 30Apr 26
20°FMay 17May 9May 3Apr 30Apr 27Apr 23Apr 19Apr 16Apr 10
16°FApr 28Apr 22Apr 18Apr 14Apr 11Apr 8Apr 4Mar 31Mar 24

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 2Sep 8Sep 11Sep 14Sep 17Sep 19Sep 22Sep 25Sep 29
32°FSep 10Sep 15Sep 19Sep 22Sep 25Sep 27Sep 30Oct 2Oct 6
28°FSep 17Sep 24Sep 27Sep 29Oct 1Oct 4Oct 7Oct 10Oct 15
24°FSep 27Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 19Oct 24
20°FOct 5Oct 10Oct 14Oct 17Oct 20Oct 23Oct 26Oct 31Nov 4
16°FOct 14Oct 18Oct 22Oct 26Oct 29Nov 1Nov 5Nov 9Nov 15

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°F10910399959187837872
32°F1271211161121091041009588
28°F150142136131127123118113106
24°F172165160155150144139132125
20°F198190185180175171166159151
16°F225216209205201196191185177

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
6,939
Cooling degree days, base 65°F
154
Growing degree days, base 40°F
3,761
Growing degree days, base 45°F
2,704
Growing degree days, base 50°F
1,813
Growing degree days, base 55°F
1,088
Growing degree days, base 60°F
527

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15800
February96500
March86002
April651018
May4101116
June13031357
July2676515
August4739457
September1837281
October519064
November84604
December1,14400

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 31.8 km from McKinley 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 USC00295560 (Mcgaffey 5 Se). Public domain.