Dike climate

Dike Frost Dates and Growing Season

NOAA 1991-2020 normals for Grundy Ctr, 15.4 km from Dike, elevation 985 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Grundy Ctr. 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 29 and the first fall freeze around October 9, a growing season of about 160 days.

Median at 36°F
last May 7, first September 30
Median at 32°F
last April 29, first October 9
Median at 28°F
last April 19, first October 18

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 21May 16May 13May 10May 7May 5May 2Apr 30Apr 25
32°FMay 12May 7May 4May 1Apr 29Apr 26Apr 23Apr 19Apr 15
28°FMay 3Apr 29Apr 25Apr 22Apr 19Apr 16Apr 12Apr 9Apr 4
24°FApr 24Apr 19Apr 15Apr 12Apr 9Apr 6Apr 2Mar 31Mar 24
20°FApr 16Apr 10Apr 5Apr 2Mar 31Mar 28Mar 24Mar 19Mar 13
16°FApr 6Apr 1Mar 29Mar 25Mar 21Mar 17Mar 14Mar 10Mar 6

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 16Sep 21Sep 25Sep 27Sep 30Oct 1Oct 4Oct 7Oct 11
32°FSep 25Sep 30Oct 3Oct 6Oct 9Oct 11Oct 14Oct 16Oct 20
28°FOct 5Oct 11Oct 14Oct 16Oct 18Oct 21Oct 23Oct 26Oct 30
24°FOct 16Oct 20Oct 23Oct 25Oct 28Oct 30Nov 1Nov 5Nov 10
20°FOct 24Oct 29Nov 1Nov 3Nov 6Nov 8Nov 11Nov 15Nov 20
16°FNov 1Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 26Dec 1

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°F161156151147144140137132126
32°F180173168164160157153148142
28°F200194188184180177172167159
24°F220214208204200196190186179
20°F243235229224219215211205199
16°F262254248243239234230223216

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
7,227
Cooling degree days, base 65°F
730
Growing degree days, base 40°F
4,890
Growing degree days, base 45°F
3,820
Growing degree days, base 50°F
2,866
Growing degree days, base 55°F
2,031
Growing degree days, base 60°F
1,315

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,47600
February1,21200
March956116
April541481
May22146310
June29172593
July7245702
August18181628
September13773393
October4709127
November876016
December1,28300

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 15.4 km from Dike. 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 USC00133487 (Grundy Ctr). Public domain.