Boyne City climate

Boyne City Frost Dates and Growing Season

NOAA 1991-2020 normals for Boyne Falls, 9.6 km from Boyne City, elevation 728 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Boyne Falls. 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 23 and the first fall freeze around October 3, a growing season of about 133 days.

Median at 36°F
last June 2, first September 19
Median at 32°F
last May 23, first October 3
Median at 28°F
last May 10, first October 16

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 21Jun 12Jun 8Jun 4Jun 2May 31May 28May 25May 21
32°FJun 6Jun 1May 29May 26May 23May 20May 17May 12May 4
28°FMay 27May 21May 18May 14May 10May 5May 1Apr 28Apr 24
24°FMay 15May 8May 2Apr 30Apr 27Apr 24Apr 21Apr 17Apr 12
20°FApr 30Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8Apr 5Mar 31
16°FApr 18Apr 14Apr 10Apr 7Apr 4Apr 2Mar 31Mar 27Mar 21

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 1Sep 7Sep 12Sep 15Sep 19Sep 22Sep 27Oct 1Oct 5
32°FSep 16Sep 22Sep 27Sep 30Oct 3Oct 5Oct 9Oct 12Oct 19
28°FSep 28Oct 3Oct 8Oct 12Oct 16Oct 19Oct 23Oct 28Nov 2
24°FOct 13Oct 20Oct 24Oct 28Nov 1Nov 3Nov 5Nov 9Nov 16
20°FOct 28Nov 2Nov 5Nov 8Nov 11Nov 14Nov 17Nov 23Nov 29
16°FNov 7Nov 11Nov 15Nov 18Nov 22Nov 26Nov 29Dec 2Dec 7

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°F130124119114110105999283
32°F156148142137133129125120112
28°F184175169164160155150144136
24°F206200195190185181176170161
20°F230223218214210206201196188
16°F254246240236231226222216211

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
7,284
Cooling degree days, base 65°F
603
Growing degree days, base 40°F
4,478
Growing degree days, base 45°F
3,452
Growing degree days, base 50°F
2,556
Growing degree days, base 55°F
1,775
Growing degree days, base 60°F
1,116

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35600
February1,19100
March1,040112
April643355
May29738250
June72117496
July21201645
August30165600
September15669372
October4879112
November827014
December1,16401

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 9.6 km from Boyne City. 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 USC00200925 (Boyne Falls). Public domain.