Dyer climate

Dyer Frost Dates and Growing Season

NOAA 1991-2020 normals for Milan Exp Stn, 28.3 km from Dyer, elevation 415 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Milan Exp Stn. 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 4 and the first fall freeze around October 28, a growing season of about 206 days.

Median at 36°F
last April 15, first October 19
Median at 32°F
last April 4, first October 28
Median at 28°F
last March 25, first November 6

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 1Apr 25Apr 22Apr 18Apr 15Apr 12Apr 8Apr 5Mar 31
32°FApr 21Apr 16Apr 11Apr 7Apr 4Apr 1Mar 30Mar 25Mar 17
28°FApr 11Apr 5Apr 1Mar 29Mar 25Mar 21Mar 17Mar 11Mar 4
24°FApr 2Mar 26Mar 20Mar 16Mar 11Mar 6Mar 2Feb 26Feb 19
20°FMar 19Mar 12Mar 6Mar 2Feb 27Feb 22Feb 18Feb 11Feb 2
16°FMar 8Mar 1Feb 24Feb 19Feb 13Feb 6Feb 1Jan 28Jan 17

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°FOct 7Oct 11Oct 14Oct 17Oct 19Oct 22Oct 24Oct 27Oct 31
32°FOct 15Oct 20Oct 23Oct 26Oct 28Oct 30Nov 1Nov 5Nov 10
28°FOct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 12Nov 17Nov 26
24°FNov 3Nov 6Nov 10Nov 14Nov 17Nov 22Nov 28Dec 1Dec 8
20°FNov 9Nov 16Nov 22Nov 28Dec 2Dec 6Dec 11Dec 20Dec 28
16°FNov 24Dec 1Dec 8Dec 13Dec 22Dec 27Jan 1Jan 6Jan 15

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°F206198193189185181177172165
32°F227218214209206201197191184
28°F252243237231226221217210203
24°F280270263256250245240234225
20°F311301292284277271264257247
16°F343331321313307301294285273

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
98% 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
3,676
Cooling degree days, base 65°F
1,766
Growing degree days, base 40°F
7,660
Growing degree days, base 45°F
6,194
Growing degree days, base 50°F
4,864
Growing degree days, base 55°F
3,686
Growing degree days, base 60°F
2,654

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January841126
February649142
March47012137
April21154318
May52174588
June2353801
July0462927
August0417882
September25228652
October19958343
November4846110
December743139

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 28.3 km from Dyer. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00406012 (Milan Exp Stn). Public domain.