Jetmore climate

Jetmore Frost Dates and Growing Season

NOAA 1991-2020 normals for Jetmore 8NNW, 12.6 km from Jetmore, elevation 2430 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jetmore 8NNW. 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 18, a growing season of about 175 days.

Median at 36°F
last May 3, first October 9
Median at 32°F
last April 25, first October 18
Median at 28°F
last April 14, first October 27

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 11May 7May 5May 3Apr 30Apr 29Apr 26Apr 21
32°FMay 6May 2Apr 30Apr 28Apr 25Apr 22Apr 19Apr 16Apr 11
28°FApr 29Apr 25Apr 21Apr 17Apr 14Apr 11Apr 7Apr 4Mar 30
24°FApr 20Apr 14Apr 10Apr 7Apr 4Mar 31Mar 28Mar 23Mar 16
20°FApr 8Apr 4Mar 31Mar 26Mar 22Mar 18Mar 14Mar 9Mar 5
16°FMar 31Mar 24Mar 18Mar 13Mar 10Mar 7Mar 4Feb 28Feb 22

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

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°F175169165161157153149145139
32°F194187183179175171167162156
28°F214207202197194189185181174
24°F235226221216212208204200193
20°F258249243238232228224217209
16°F279272266260254249243236227

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
5,190
Cooling degree days, base 65°F
1,435
Growing degree days, base 40°F
6,378
Growing degree days, base 45°F
5,106
Growing degree days, base 50°F
3,984
Growing degree days, base 55°F
3,004
Growing degree days, base 60°F
2,155

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05401
February86808
March668156
April38613159
May14587417
June15283719
July2453916
August3390852
September62180571
October31428238
November679144
December99603

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 12.6 km from Jetmore. 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 USC00144087 (Jetmore 8NNW). Public domain.