Kilmanagh climate

Kilmanagh Frost Dates and Growing Season

NOAA 1991-2020 normals for Cass City 1 Ssw, 23.6 km from Kilmanagh, elevation 698 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cass City 1 Ssw. 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 May 7 and the first fall freeze around October 10, a growing season of about 152 days.

Median at 36°F
last May 19, first September 30
Median at 32°F
last May 7, first October 10
Median at 28°F
last April 28, first October 24

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 31May 28May 25May 22May 19May 17May 13May 10May 5
32°FMay 22May 19May 15May 11May 7May 4May 1Apr 29Apr 25
28°FMay 14May 7May 3Apr 30Apr 28Apr 24Apr 21Apr 19Apr 13
24°FApr 30Apr 23Apr 20Apr 18Apr 15Apr 12Apr 8Apr 4Mar 31
20°FApr 17Apr 11Apr 7Apr 4Apr 2Mar 31Mar 28Mar 22Mar 17
16°FApr 4Mar 31Mar 29Mar 26Mar 22Mar 19Mar 17Mar 13Mar 8

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 16Sep 21Sep 24Sep 27Sep 30Oct 2Oct 5Oct 8Oct 12
32°FSep 26Oct 1Oct 4Oct 6Oct 10Oct 13Oct 16Oct 20Oct 25
28°FOct 6Oct 13Oct 17Oct 20Oct 24Oct 27Oct 30Nov 2Nov 6
24°FOct 22Oct 29Nov 1Nov 2Nov 5Nov 8Nov 11Nov 15Nov 20
20°FNov 4Nov 8Nov 12Nov 15Nov 17Nov 20Nov 23Nov 27Dec 2
16°FNov 11Nov 17Nov 21Nov 24Nov 27Dec 1Dec 4Dec 8Dec 16

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°F151145140135131128124120114
32°F173165161156152147143138131
28°F197190185180176172167161152
24°F224216211207203199194189182
20°F249242236232228223219214208
16°F272264258254249245241235228

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
7,376
Cooling degree days, base 65°F
410
Growing degree days, base 40°F
4,174
Growing degree days, base 45°F
3,151
Growing degree days, base 50°F
2,263
Growing degree days, base 55°F
1,498
Growing degree days, base 60°F
870

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,37200
February1,19100
March1,019111
April645144
May32023210
June7994465
July24141583
August41109533
September18036315
October508591
November834010
December1,16401

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 23.6 km from Kilmanagh. 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 USC00201361 (Cass City 1 Ssw). Public domain.