Munising climate

Munising Frost Dates and Growing Season

NOAA 1991-2020 normals for Munising, 1 km from Munising, elevation 680 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Munising. 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 16 and the first fall freeze around October 14, a growing season of about 148 days.

Median at 36°F
last May 30, first October 1
Median at 32°F
last May 16, first October 14
Median at 28°F
last May 3, first October 28

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 12Jun 7Jun 4Jun 1May 30May 28May 24May 20May 15
32°FJun 2May 27May 23May 19May 16May 13May 9May 6May 1
28°FMay 20May 14May 10May 6May 3Apr 30Apr 28Apr 25Apr 19
24°FMay 7May 1Apr 27Apr 25Apr 21Apr 18Apr 16Apr 12Apr 8
20°FApr 24Apr 19Apr 15Apr 12Apr 10Apr 7Apr 4Apr 2Mar 28
16°FApr 14Apr 9Apr 6Apr 4Apr 2Mar 31Mar 27Mar 22Mar 16

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 17Sep 23Sep 26Sep 29Oct 1Oct 4Oct 7Oct 10Oct 14
32°FSep 30Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21Oct 24Oct 30
28°FOct 11Oct 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 5Nov 11
24°FOct 26Oct 31Nov 1Nov 4Nov 7Nov 11Nov 14Nov 17Nov 22
20°FNov 3Nov 7Nov 11Nov 14Nov 17Nov 20Nov 24Nov 27Dec 2
16°FNov 9Nov 15Nov 19Nov 24Nov 26Nov 29Dec 2Dec 6Dec 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°F143137132128124121117113105
32°F169162157153148144140135128
28°F195188183179174170165159152
24°F220213207202198194190184177
20°F241234230225222217213208201
16°F260252247243238234230225218

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
8,907
Cooling degree days, base 65°F
169
Growing degree days, base 40°F
3,095
Growing degree days, base 45°F
2,231
Growing degree days, base 50°F
1,497
Growing degree days, base 55°F
897
Growing degree days, base 60°F
447

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,47600
February1,30500
March1,20302
April854010
May5066101
June23130267
July10071437
August9848416
September26515223
October631140
November95102
December1,28800

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 1 km from Munising. 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 USC00205690 (Munising). Public domain.