Clio climate

Clio Frost Dates and Growing Season

NOAA 1991-2020 normals for Flint 7W, 15.9 km from Clio, elevation 679 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Flint 7W. 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 May 3 and the first fall freeze around October 13, a growing season of about 162 days.

Median at 36°F
last May 14, first October 2
Median at 32°F
last May 3, first October 13
Median at 28°F
last April 22, first October 27

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 25May 21May 17May 14May 11May 7May 3Apr 29
32°FMay 20May 14May 10May 5May 3Apr 30Apr 28Apr 24Apr 20
28°FMay 9May 2Apr 29Apr 25Apr 22Apr 20Apr 17Apr 13Apr 8
24°FApr 23Apr 19Apr 15Apr 13Apr 9Apr 7Apr 4Apr 1Mar 27
20°FApr 12Apr 7Apr 4Apr 2Mar 31Mar 28Mar 24Mar 19Mar 14
16°FApr 3Mar 31Mar 27Mar 23Mar 20Mar 17Mar 15Mar 12Mar 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 20Sep 24Sep 28Sep 30Oct 2Oct 4Oct 6Oct 9Oct 13
32°FSep 30Oct 4Oct 7Oct 10Oct 13Oct 16Oct 19Oct 23Oct 27
28°FOct 12Oct 18Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 9
24°FOct 24Oct 31Nov 2Nov 4Nov 7Nov 10Nov 14Nov 17Nov 23
20°FNov 4Nov 9Nov 13Nov 16Nov 19Nov 22Nov 27Dec 1Dec 6
16°FNov 13Nov 19Nov 23Nov 27Dec 1Dec 3Dec 8Dec 13Dec 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°F159153148144141138133128122
32°F181175170166162157153147142
28°F206200195190186182176171163
24°F232225220215212207203197190
20°F257249243239235231226220213
16°F278271265261255250246240233

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
6,910
Cooling degree days, base 65°F
559
Growing degree days, base 40°F
4,561
Growing degree days, base 45°F
3,491
Growing degree days, base 50°F
2,559
Growing degree days, base 55°F
1,757
Growing degree days, base 60°F
1,082

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29600
February1,13301
March982114
April586156
May27027253
June55118514
July14202652
August23152594
September15354356
October4765105
November794014
December1,12801

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 15.9 km from Clio. 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 USC00202851 (Flint 7W). Public domain.