Clarkston climate

Clarkston Frost Dates and Growing Season

NOAA 1991-2020 normals for White Lake 4E, 6 km from Clarkston, elevation 1053 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for White Lake 4E. 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 10 and the first fall freeze around October 6, a growing season of about 148 days.

Median at 36°F
last May 24, first September 26
Median at 32°F
last May 10, first October 6
Median at 28°F
last April 28, first October 19

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°FJun 6Jun 2May 30May 27May 24May 20May 17May 12May 7
32°FMay 26May 21May 17May 13May 10May 6May 2Apr 30Apr 25
28°FMay 15May 9May 5May 1Apr 28Apr 25Apr 22Apr 19Apr 15
24°FApr 30Apr 26Apr 22Apr 19Apr 17Apr 15Apr 11Apr 7Apr 3
20°FApr 18Apr 15Apr 11Apr 8Apr 5Apr 3Apr 1Mar 30Mar 22
16°FApr 10Apr 5Apr 2Mar 31Mar 28Mar 24Mar 20Mar 16Mar 12

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 13Sep 18Sep 21Sep 24Sep 26Sep 28Oct 1Oct 3Oct 7
32°FSep 24Sep 28Oct 1Oct 4Oct 6Oct 9Oct 12Oct 16Oct 21
28°FOct 4Oct 8Oct 12Oct 16Oct 19Oct 22Oct 25Oct 29Nov 2
24°FOct 17Oct 22Oct 26Oct 29Nov 1Nov 3Nov 5Nov 10Nov 15
20°FOct 29Nov 2Nov 5Nov 8Nov 11Nov 14Nov 17Nov 22Nov 28
16°FNov 7Nov 12Nov 16Nov 19Nov 22Nov 26Nov 29Dec 3Dec 9

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°F145139133129125121117112105
32°F168161156152148144140135128
28°F191185180176171168162156149
24°F217211205201197193189184176
20°F242235228222218215211206200
16°F264256251247242238233227220

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
7,401
Cooling degree days, base 65°F
360
Growing degree days, base 40°F
4,132
Growing degree days, base 45°F
3,101
Growing degree days, base 50°F
2,201
Growing degree days, base 55°F
1,430
Growing degree days, base 60°F
806

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,36100
February1,18400
March1,005012
April624253
May31118212
June9075436
July32127559
August4798516
September18935308
October516491
November848013
December1,19501

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 6 km from Clarkston. 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 USC00208941 (White Lake 4E). Public domain.