Nicollet County climate

Nicollet County Frost Dates and Growing Season

NOAA 1991-2020 normals for New Ulm 3SE, 14.2 km from Nicollet County, elevation 925 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for New Ulm 3SE. 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 2 and the first fall freeze around October 7, a growing season of about 157 days.

Median at 36°F
last May 11, first September 28
Median at 32°F
last May 2, first October 7
Median at 28°F
last April 20, first October 18

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 18May 15May 13May 11May 8May 6May 3Apr 30
32°FMay 14May 10May 7May 4May 2Apr 30Apr 27Apr 23Apr 17
28°FMay 4Apr 30Apr 27Apr 24Apr 20Apr 17Apr 14Apr 9Apr 5
24°FApr 26Apr 21Apr 17Apr 13Apr 10Apr 7Apr 5Apr 2Mar 29
20°FApr 17Apr 12Apr 8Apr 6Apr 4Apr 2Mar 30Mar 25Mar 18
16°FApr 11Apr 6Apr 3Apr 1Mar 29Mar 24Mar 20Mar 16Mar 11

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 23Sep 26Sep 28Oct 1Oct 3Oct 7Oct 11
32°FSep 23Sep 28Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20
28°FOct 2Oct 8Oct 12Oct 16Oct 18Oct 21Oct 24Oct 27Oct 31
24°FOct 16Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 7Nov 12
20°FOct 25Oct 30Nov 1Nov 4Nov 7Nov 10Nov 12Nov 15Nov 20
16°FNov 2Nov 5Nov 9Nov 11Nov 14Nov 16Nov 19Nov 23Nov 28

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°F157150146142138135132128122
32°F177169165161157153149145138
28°F200193188183179175170165159
24°F219212208204200196192187180
20°F236229225220216213208204197
16°F251245240236231227223217211

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
8,077
Cooling degree days, base 65°F
542
Growing degree days, base 40°F
4,426
Growing degree days, base 45°F
3,419
Growing degree days, base 50°F
2,518
Growing degree days, base 55°F
1,734
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
January1,60200
February1,34400
March1,082011
April619160
May27328250
June42116523
July9194649
August25145584
September16854347
October544487
November96807
December1,39900

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 14.2 km from Nicollet County. 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 USC00215888 (New Ulm 3SE). Public domain.