Houghton County climate

Houghton County Frost Dates and Growing Season

NOAA 1991-2020 normals for Jacobsville, 16.8 km from Houghton County, elevation 650 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jacobsville. 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 June 1 and the first fall freeze around September 23, a growing season of about 115 days.

Median at 36°F
last June 14, first September 11
Median at 32°F
last June 1, first September 23
Median at 28°F
last May 14, first October 7

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°FJul 5Jun 27Jun 21Jun 17Jun 14Jun 10Jun 6Jun 3May 29
32°FJun 17Jun 11Jun 6Jun 3Jun 1May 29May 25May 21May 14
28°FJun 4May 29May 23May 18May 14May 11May 8May 4Apr 30
24°FMay 18May 12May 6May 2Apr 30Apr 27Apr 24Apr 20Apr 14
20°FMay 1Apr 27Apr 23Apr 20Apr 17Apr 14Apr 11Apr 8Apr 4
16°FApr 21Apr 17Apr 13Apr 10Apr 8Apr 6Apr 3Apr 1Mar 28

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°FAug 27Sep 1Sep 4Sep 8Sep 11Sep 14Sep 17Sep 21Sep 26
32°FSep 9Sep 13Sep 18Sep 20Sep 23Sep 27Sep 30Oct 3Oct 7
28°FSep 20Sep 26Sep 30Oct 4Oct 7Oct 10Oct 13Oct 18Oct 23
24°FOct 6Oct 12Oct 17Oct 21Oct 25Oct 28Nov 1Nov 3Nov 8
20°FOct 28Nov 1Nov 2Nov 4Nov 7Nov 10Nov 12Nov 16Nov 21
16°FNov 4Nov 8Nov 11Nov 14Nov 17Nov 20Nov 22Nov 26Nov 30

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°F11010396928883787161
32°F13412812311911511110610294
28°F167159154149143140135129121
24°F196189185180176171166159153
20°F222215210206204200196190183
16°F239233229225222218214210205

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
9,238
Cooling degree days, base 65°F
137
Growing degree days, base 40°F
2,964
Growing degree days, base 45°F
2,106
Growing degree days, base 50°F
1,387
Growing degree days, base 55°F
811
Growing degree days, base 60°F
390

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,50900
February1,34500
March1,27903
April85706
May532275
June24315238
July9859427
August11445397
September29415204
October658137
November97702
December1,33300

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 16.8 km from Houghton County. 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 USC00204161 (Jacobsville). Public domain.