Stevensville climate

Stevensville Frost Dates and Growing Season

NOAA 1991-2020 normals for Benton Harbor AP, 14.4 km from Stevensville, elevation 625 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Benton Harbor AP. 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 5 and the first fall freeze around October 15, a growing season of about 161 days.

Median at 36°F
last May 21, first October 3
Median at 32°F
last May 5, first October 15
Median at 28°F
last April 25, first October 30

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 8Jun 2May 29May 26May 21May 18May 14May 8May 2
32°FMay 26May 19May 14May 9May 5May 2Apr 30Apr 26Apr 20
28°FMay 11May 4May 1Apr 28Apr 25Apr 22Apr 18Apr 14Apr 10
24°FApr 29Apr 23Apr 19Apr 15Apr 12Apr 8Apr 5Apr 2Mar 29
20°FApr 17Apr 10Apr 5Apr 2Mar 31Mar 28Mar 25Mar 21Mar 15
16°FApr 3Mar 30Mar 26Mar 23Mar 20Mar 16Mar 14Mar 9Mar 2

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 18Sep 23Sep 27Sep 30Oct 3Oct 5Oct 8Oct 11Oct 17
32°FSep 28Oct 4Oct 8Oct 11Oct 15Oct 18Oct 22Oct 26Nov 1
28°FOct 14Oct 19Oct 23Oct 26Oct 30Nov 2Nov 5Nov 8Nov 14
24°FOct 29Nov 2Nov 5Nov 8Nov 12Nov 15Nov 20Nov 25Dec 1
20°FNov 8Nov 13Nov 18Nov 22Nov 26Nov 30Dec 3Dec 7Dec 13
16°FNov 19Nov 25Nov 30Dec 3Dec 6Dec 10Dec 15Dec 20Dec 26

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°F159152147141136131126121112
32°F184177171166161156151145136
28°F209202196192188183178172163
24°F234228222217213208203198190
20°F263255249243239235230224218
16°F286279274268262257252248239

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
6,160
Cooling degree days, base 65°F
770
Growing degree days, base 40°F
5,102
Growing degree days, base 45°F
3,957
Growing degree days, base 50°F
2,955
Growing degree days, base 55°F
2,085
Growing degree days, base 60°F
1,351

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19801
February1,02302
March863329
April514795
May25050292
June57149543
July15250701
August21204648
September10794440
October37214169
November702032
December1,03703

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 14.4 km from Stevensville. 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 USC00200710 (Benton Harbor AP). Public domain.