Dryden climate

Dryden Frost Dates and Growing Season

NOAA 1991-2020 normals for Lapeer Wwtp, 19.6 km from Dryden, elevation 820 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lapeer Wwtp. 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 4 and the first fall freeze around October 14, a growing season of about 160 days.

Median at 36°F
last May 17, first October 2
Median at 32°F
last May 4, first October 14
Median at 28°F
last April 24, 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 31May 27May 24May 20May 17May 13May 10May 5Apr 30
32°FMay 22May 16May 12May 8May 4May 1Apr 30Apr 26Apr 22
28°FMay 10May 4Apr 30Apr 28Apr 24Apr 21Apr 19Apr 15Apr 8
24°FApr 26Apr 21Apr 18Apr 15Apr 11Apr 7Apr 4Apr 2Mar 28
20°FApr 16Apr 10Apr 6Apr 3Apr 1Mar 31Mar 27Mar 22Mar 17
16°FApr 4Mar 31Mar 29Mar 24Mar 21Mar 18Mar 15Mar 12Mar 7

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 7Oct 10Oct 14
32°FSep 29Oct 3Oct 7Oct 10Oct 14Oct 17Oct 20Oct 24Oct 28
28°FOct 12Oct 19Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 10
24°FOct 27Nov 1Nov 2Nov 5Nov 8Nov 11Nov 15Nov 18Nov 23
20°FNov 3Nov 8Nov 12Nov 16Nov 19Nov 23Nov 27Dec 1Dec 5
16°FNov 12Nov 19Nov 23Nov 28Dec 1Dec 3Dec 7Dec 12Dec 19

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°F158151146142138134130125118
32°F180175170165160156151147140
28°F206198194190186181177171162
24°F232225220215211207203197189
20°F255247243238233228224218211
16°F278269263258253248244239231

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
6,942
Cooling degree days, base 65°F
571
Growing degree days, base 40°F
4,576
Growing degree days, base 45°F
3,506
Growing degree days, base 50°F
2,576
Growing degree days, base 55°F
1,772
Growing degree days, base 60°F
1,098

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,31600
February1,14500
March985114
April605358
May28136255
June62118508
July14197648
August25152592
September14657367
October4546116
November789016
December1,12102

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 19.6 km from Dryden. 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 USC00204655 (Lapeer Wwtp). Public domain.