Maple Plain climate

Maple Plain Frost Dates and Growing Season

NOAA 1991-2020 normals for Chanhassen Wsfo, 18.9 km from Maple Plain, elevation 946 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chanhassen Wsfo. 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 April 30 and the first fall freeze around October 9, a growing season of about 160 days.

Median at 36°F
last May 9, first September 30
Median at 32°F
last April 30, first October 9
Median at 28°F
last April 19, 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°FMay 24May 19May 15May 12May 9May 7May 5May 1Apr 27
32°FMay 15May 9May 6May 2Apr 30Apr 27Apr 24Apr 20Apr 15
28°FMay 4Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 4
24°FApr 23Apr 18Apr 15Apr 11Apr 8Apr 6Apr 4Apr 1Mar 27
20°FApr 16Apr 9Apr 6Apr 4Apr 2Mar 31Mar 27Mar 22Mar 17
16°FApr 7Apr 3Apr 1Mar 29Mar 26Mar 22Mar 19Mar 15Mar 10

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 17Sep 21Sep 24Sep 27Sep 30Oct 2Oct 4Oct 7Oct 11
32°FSep 25Sep 30Oct 3Oct 6Oct 9Oct 12Oct 14Oct 17Oct 21
28°FOct 4Oct 10Oct 13Oct 17Oct 19Oct 22Oct 24Oct 27Oct 31
24°FOct 14Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 10
20°FOct 25Oct 30Nov 1Nov 3Nov 6Nov 9Nov 11Nov 14Nov 20
16°FNov 2Nov 5Nov 9Nov 11Nov 14Nov 17Nov 20Nov 24Nov 27

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°F159153149145142138134129123
32°F178172167163160156152146140
28°F200193188185180177173168161
24°F220213208204199196192187181
20°F236229225221217213210204197
16°F251244239236232228224220213

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
7,980
Cooling degree days, base 65°F
583
Growing degree days, base 40°F
4,479
Growing degree days, base 45°F
3,469
Growing degree days, base 50°F
2,566
Growing degree days, base 55°F
1,777
Growing degree days, base 60°F
1,113

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,58100
February1,31600
March1,056010
April602260
May26728253
June48123525
July9218674
August18154601
September16653348
October549588
November96808
December1,40300

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 18.9 km from Maple Plain. 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 USC00211448 (Chanhassen Wsfo). Public domain.