Monon climate

Monon Frost Dates and Growing Season

NOAA 1991-2020 normals for Francesville, 12.9 km from Monon, elevation 680 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Francesville. 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 26 and the first fall freeze around October 17, a growing season of about 173 days.

Median at 36°F
last May 6, first October 6
Median at 32°F
last April 26, first October 17
Median at 28°F
last April 16, 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°FMay 22May 16May 11May 8May 6May 3Apr 30Apr 28Apr 23
32°FMay 12May 6May 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 12
28°FMay 1Apr 24Apr 22Apr 18Apr 16Apr 12Apr 8Apr 5Apr 1
24°FApr 19Apr 14Apr 9Apr 6Apr 3Apr 1Mar 30Mar 25Mar 19
20°FApr 6Apr 2Mar 31Mar 28Mar 24Mar 21Mar 16Mar 12Mar 6
16°FMar 29Mar 24Mar 19Mar 16Mar 13Mar 10Mar 7Mar 2Feb 24

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

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°F171164159156152148144140132
32°F192186180177173169165159152
28°F214207203199194190187182173
24°F238230225220217213209204197
20°F264255250244239234229224217
16°F286276270265260255250245237

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
6,292
Cooling degree days, base 65°F
772
Growing degree days, base 40°F
5,199
Growing degree days, base 45°F
4,061
Growing degree days, base 50°F
3,048
Growing degree days, base 55°F
2,158
Growing degree days, base 60°F
1,394

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28601
February1,05802
March854126
April4815111
May19458344
June30172593
July7242701
August12194646
September10087439
October40113159
November756023
December1,11304

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 12.9 km from Monon. 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 USC00123078 (Francesville). Public domain.