Morgandale climate

Morgandale Frost Dates and Growing Season

NOAA 1991-2020 normals for Mosquito Creek Lake, 3.9 km from Morgandale, elevation 910 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mosquito Creek Lake. 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 30 and the first fall freeze around October 23, a growing season of about 176 days.

Median at 36°F
last May 11, first October 10
Median at 32°F
last April 30, first October 23
Median at 28°F
last April 18, first November 5

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 27May 22May 18May 14May 11May 7May 3Apr 30Apr 26
32°FMay 16May 10May 5May 2Apr 30Apr 27Apr 24Apr 20Apr 16
28°FMay 2Apr 27Apr 23Apr 20Apr 18Apr 16Apr 13Apr 9Apr 4
24°FApr 19Apr 15Apr 12Apr 8Apr 6Apr 3Mar 31Mar 27Mar 19
20°FApr 9Apr 4Apr 1Mar 31Mar 27Mar 23Mar 19Mar 14Mar 8
16°FMar 31Mar 26Mar 21Mar 17Mar 14Mar 11Mar 8Mar 4Feb 27

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 28Oct 1Oct 4Oct 7Oct 10Oct 13Oct 17Oct 20Oct 25
32°FOct 7Oct 13Oct 17Oct 20Oct 23Oct 27Oct 31Nov 2Nov 7
28°FOct 23Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 14Nov 20
24°FNov 4Nov 9Nov 12Nov 14Nov 17Nov 20Nov 23Nov 28Dec 5
20°FNov 12Nov 17Nov 21Nov 25Nov 30Dec 3Dec 6Dec 11Dec 18
16°FNov 21Nov 28Dec 2Dec 7Dec 11Dec 15Dec 20Dec 24Dec 30

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°F175167163158154149144139132
32°F196190185180176172167162156
28°F221215210205201197193187179
24°F250242235231227222217213206
20°F272263257253248243237232226
16°F294285279275269264259252245

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
6,282
Cooling degree days, base 65°F
556
Growing degree days, base 40°F
4,843
Growing degree days, base 45°F
3,698
Growing degree days, base 50°F
2,707
Growing degree days, base 55°F
1,848
Growing degree days, base 60°F
1,120

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,20201
February1,03903
March919223
April531180
May23230293
June47103506
July10198652
August20153598
September12362392
October4267133
November717023
December1,01703

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 3.9 km from Morgandale. 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 USC00335505 (Mosquito Creek Lake). Public domain.