Motley climate

Motley Frost Dates and Growing Season

NOAA 1991-2020 normals for Chatham, 28.3 km from Motley, elevation 647 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chatham. 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 22 and the first fall freeze around October 23, a growing season of about 183 days.

Median at 36°F
last May 3, first October 13
Median at 32°F
last April 22, first October 23
Median at 28°F
last April 9, first November 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°FMay 20May 14May 9May 6May 3Apr 30Apr 28Apr 24Apr 19
32°FMay 9May 2Apr 30Apr 25Apr 22Apr 19Apr 16Apr 13Apr 7
28°FApr 24Apr 19Apr 16Apr 12Apr 9Apr 5Apr 2Mar 29Mar 23
24°FApr 10Apr 5Apr 2Mar 30Mar 27Mar 24Mar 20Mar 15Mar 9
20°FMar 31Mar 27Mar 21Mar 17Mar 13Mar 9Mar 5Mar 1Feb 23
16°FMar 20Mar 12Mar 8Mar 4Feb 28Feb 24Feb 19Feb 10Feb 1

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 2Oct 5Oct 8Oct 11Oct 13Oct 16Oct 19Oct 23Oct 27
32°FOct 9Oct 14Oct 18Oct 21Oct 23Oct 26Oct 29Nov 1Nov 4
28°FOct 18Oct 24Oct 27Oct 31Nov 1Nov 3Nov 5Nov 8Nov 13
24°FOct 29Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 22Nov 30
20°FNov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 2Dec 6Dec 17
16°FNov 21Nov 27Dec 1Dec 5Dec 10Dec 16Dec 23Jan 1Jan 8

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°F182176170167163159155149143
32°F204197192187183178173169162
28°F228220214210206202198193186
24°F253245240234229225221216209
20°F288276269263258252247241232
16°F321308301295288281275268259

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
4,450
Cooling degree days, base 65°F
1,043
Growing degree days, base 40°F
6,251
Growing degree days, base 45°F
4,885
Growing degree days, base 50°F
3,686
Growing degree days, base 55°F
2,651
Growing degree days, base 60°F
1,770

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January90708
February746013
March606163
April31414196
May12371416
June16207640
July1326790
August2283746
September51124524
October28817223
November581152
December817015

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 28.3 km from Motley. 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 USC00441614 (Chatham). Public domain.