Ackermanville climate

Ackermanville Frost Dates and Growing Season

NOAA 1991-2020 normals for Belvidere Brg, 11.5 km from Ackermanville, elevation 263 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Belvidere Brg. 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 18, a growing season of about 168 days.

Median at 36°F
last May 12, first October 6
Median at 32°F
last April 30, first October 18
Median at 28°F
last April 16, first October 29

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 29May 24May 20May 16May 12May 9May 5Apr 30Apr 26
32°FMay 18May 11May 7May 3Apr 30Apr 26Apr 23Apr 20Apr 15
28°FMay 5Apr 26Apr 22Apr 19Apr 16Apr 12Apr 9Apr 6Apr 2
24°FApr 16Apr 11Apr 7Apr 5Apr 3Apr 1Mar 30Mar 25Mar 20
20°FApr 4Mar 31Mar 29Mar 26Mar 22Mar 19Mar 16Mar 12Mar 6
16°FMar 25Mar 21Mar 17Mar 14Mar 10Mar 7Mar 4Feb 28Feb 22

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

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°F168161156151147143138133125
32°F191184178173168164159154145
28°F214208204199195190185180172
24°F239232228223219216211206200
20°F265257252248243239235229222
16°F293286279274270264260253246

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
6,050
Cooling degree days, base 65°F
650
Growing degree days, base 40°F
4,958
Growing degree days, base 45°F
3,808
Growing degree days, base 50°F
2,807
Growing degree days, base 55°F
1,942
Growing degree days, base 60°F
1,225

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17001
February1,00200
March868010
April502377
May23027274
June47119522
July4231691
August8194651
September9871425
October4016135
November711019
December1,00802

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 11.5 km from Ackermanville. 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 USC00280734 (Belvidere Brg). Public domain.