Glencoe climate

Glencoe Frost Dates and Growing Season

NOAA 1991-2020 normals for Brownton Wwtp, 15.5 km from Glencoe, elevation 1040 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brownton Wwtp. 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 30 and the first fall freeze around October 4, a growing season of about 156 days.

Median at 36°F
last May 10, first September 26
Median at 32°F
last April 30, first October 4
Median at 28°F
last April 20, first October 15

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 24May 18May 15May 12May 10May 7May 5May 2Apr 28
32°FMay 13May 9May 6May 3Apr 30Apr 29Apr 25Apr 22Apr 17
28°FMay 3Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10Apr 6
24°FApr 23Apr 19Apr 15Apr 13Apr 10Apr 7Apr 5Apr 2Mar 30
20°FApr 17Apr 11Apr 7Apr 5Apr 3Apr 1Mar 30Mar 24Mar 19
16°FApr 10Apr 5Apr 2Mar 31Mar 28Mar 24Mar 21Mar 17Mar 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 14Sep 19Sep 21Sep 24Sep 26Sep 29Oct 1Oct 4Oct 8
32°FSep 21Sep 26Sep 29Oct 1Oct 4Oct 6Oct 9Oct 13Oct 18
28°FSep 30Oct 5Oct 8Oct 12Oct 15Oct 17Oct 20Oct 23Oct 27
24°FOct 12Oct 18Oct 21Oct 24Oct 26Oct 28Oct 30Nov 2Nov 8
20°FOct 23Oct 27Oct 30Nov 1Nov 4Nov 7Nov 9Nov 13Nov 18
16°FNov 1Nov 4Nov 7Nov 10Nov 12Nov 15Nov 18Nov 22Nov 27

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°F156150145142139135132127120
32°F176169164159156153149143137
28°F195190185181177173169164157
24°F214209205201197194190185179
20°F233226221217214210206201195
16°F249242237233229224220216209

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
8,271
Cooling degree days, base 65°F
535
Growing degree days, base 40°F
4,368
Growing degree days, base 45°F
3,375
Growing degree days, base 50°F
2,486
Growing degree days, base 55°F
1,713
Growing degree days, base 60°F
1,056

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,63400
February1,36800
March1,11007
April628156
May27031257
June43118525
July11195649
August26141579
September18146328
October560480
November1,00104
December1,44100

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 15.5 km from Glencoe. 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 USC00211065 (Brownton Wwtp). Public domain.