Minnetrista climate

Minnetrista Frost Dates and Growing Season

NOAA 1991-2020 normals for Chaska 2NW, 15.5 km from Minnetrista, elevation 923 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chaska 2NW. 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 5, a growing season of about 151 days.

Median at 36°F
last May 16, first September 27
Median at 32°F
last May 5, first October 5
Median at 28°F
last April 23, 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°FMay 29May 23May 21May 18May 16May 13May 10May 8May 4
32°FMay 19May 14May 10May 7May 5May 3Apr 30Apr 27Apr 21
28°FMay 6May 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 8
24°FApr 26Apr 21Apr 18Apr 15Apr 12Apr 9Apr 7Apr 4Apr 1
20°FApr 19Apr 14Apr 9Apr 7Apr 4Apr 3Apr 1Mar 28Mar 21
16°FApr 11Apr 6Apr 3Apr 1Mar 31Mar 28Mar 24Mar 20Mar 14

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 15Sep 19Sep 22Sep 24Sep 27Sep 30Oct 2Oct 5Oct 8
32°FSep 22Sep 27Sep 30Oct 2Oct 5Oct 7Oct 10Oct 14Oct 18
28°FOct 1Oct 6Oct 10Oct 13Oct 16Oct 18Oct 21Oct 24Oct 28
24°FOct 12Oct 17Oct 21Oct 23Oct 26Oct 29Nov 1Nov 4Nov 8
20°FOct 22Oct 27Oct 31Nov 1Nov 4Nov 6Nov 10Nov 14Nov 19
16°FOct 31Nov 3Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23Nov 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°F149144139136133129125121115
32°F169163159155151147143139133
28°F192185181177174170166161155
24°F212206202198195191187182177
20°F231224219215212209205200193
16°F245240235231227223219214209

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
8,138
Cooling degree days, base 65°F
557
Growing degree days, base 40°F
4,377
Growing degree days, base 45°F
3,377
Growing degree days, base 50°F
2,486
Growing degree days, base 55°F
1,715
Growing degree days, base 60°F
1,070

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,60400
February1,33600
March1,096010
April624151
May29522224
June56108503
July11209663
August25152592
September16458355
October553685
November97403
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 15.5 km from Minnetrista. 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 USC00211468 (Chaska 2NW). Public domain.