Coleman climate

Coleman Frost Dates and Growing Season

NOAA 1991-2020 normals for Gladwin, 25.5 km from Coleman, elevation 775 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gladwin. 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 9 and the first fall freeze around October 4, a growing season of about 148 days.

Median at 36°F
last May 22, first September 26
Median at 32°F
last May 9, first October 4
Median at 28°F
last April 30, first October 17

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°FJun 3May 31May 27May 25May 22May 20May 16May 13May 7
32°FMay 23May 19May 16May 12May 9May 6May 3Apr 30Apr 26
28°FMay 14May 8May 5May 1Apr 30Apr 27Apr 24Apr 20Apr 14
24°FMay 2Apr 28Apr 24Apr 20Apr 18Apr 15Apr 12Apr 8Apr 3
20°FApr 20Apr 16Apr 12Apr 8Apr 6Apr 3Apr 1Mar 29Mar 22
16°FApr 11Apr 6Apr 3Apr 1Mar 29Mar 25Mar 22Mar 18Mar 13

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 11Sep 17Sep 20Sep 23Sep 26Sep 29Oct 1Oct 4Oct 8
32°FSep 22Sep 27Oct 1Oct 2Oct 4Oct 7Oct 10Oct 13Oct 19
28°FOct 1Oct 6Oct 10Oct 14Oct 17Oct 20Oct 23Oct 28Nov 1
24°FOct 14Oct 21Oct 25Oct 29Nov 1Nov 3Nov 7Nov 11Nov 16
20°FOct 28Nov 2Nov 6Nov 10Nov 14Nov 17Nov 20Nov 25Dec 1
16°FNov 8Nov 15Nov 19Nov 23Nov 27Nov 30Dec 2Dec 7Dec 13

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°F144137133130125122118113107
32°F169162156152148144139134129
28°F192185179174169165161156149
24°F218210205201197193187181173
20°F242235230225221217212207201
16°F264257250246241237232227220

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
7,425
Cooling degree days, base 65°F
428
Growing degree days, base 40°F
4,168
Growing degree days, base 45°F
3,154
Growing degree days, base 50°F
2,274
Growing degree days, base 55°F
1,521
Growing degree days, base 60°F
898

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,36500
February1,19700
March1,03907
April654141
May31623213
June7689464
July20161606
August37116544
September18335312
October522379
November84208
December1,17500

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 25.5 km from Coleman. 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 USW00014828 (Gladwin). Public domain.