Charlevoix climate

Charlevoix Frost Dates and Growing Season

NOAA 1991-2020 normals for Charlevoix, 0.7 km from Charlevoix, elevation 593 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Charlevoix. 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 1 and the first fall freeze around October 28, a growing season of about 178 days.

Median at 36°F
last May 12, first October 14
Median at 32°F
last May 1, first October 28
Median at 28°F
last April 19, first November 9

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 27May 22May 18May 15May 12May 9May 6May 2Apr 30
32°FMay 16May 9May 5May 3May 1Apr 29Apr 26Apr 23Apr 18
28°FMay 1Apr 28Apr 24Apr 21Apr 19Apr 17Apr 14Apr 11Apr 6
24°FApr 21Apr 17Apr 14Apr 11Apr 9Apr 7Apr 4Apr 1Mar 28
20°FApr 14Apr 9Apr 7Apr 4Apr 2Mar 31Mar 28Mar 24Mar 19
16°FApr 8Apr 4Apr 1Mar 30Mar 27Mar 23Mar 20Mar 17Mar 13

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 1Oct 5Oct 9Oct 12Oct 14Oct 17Oct 19Oct 24Oct 29
32°FOct 13Oct 18Oct 22Oct 25Oct 28Nov 1Nov 3Nov 5Nov 11
28°FOct 27Oct 31Nov 3Nov 5Nov 9Nov 12Nov 15Nov 19Nov 24
24°FNov 5Nov 11Nov 15Nov 19Nov 22Nov 25Nov 28Dec 1Dec 7
20°FNov 14Nov 21Nov 25Nov 30Dec 2Dec 6Dec 9Dec 14Dec 20
16°FNov 24Dec 1Dec 6Dec 9Dec 13Dec 17Dec 21Dec 24Dec 31

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°F172166162157154150146141134
32°F198191186182178174170165159
28°F223216210206203200195190183
24°F245239234229225221217212207
20°F264258252247243239235229220
16°F283276271267262257251245238

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
7,438
Cooling degree days, base 65°F
379
Growing degree days, base 40°F
3,984
Growing degree days, base 45°F
2,993
Growing degree days, base 50°F
2,135
Growing degree days, base 55°F
1,408
Growing degree days, base 60°F
814

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29900
February1,18900
March1,10405
April743022
May4129138
June13155376
July29142578
August26122561
September15147351
October479494
November77909
December1,09900

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 0.7 km from Charlevoix. 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 USC00201468 (Charlevoix). Public domain.