Wright County climate

Wright County Frost Dates and Growing Season

NOAA 1991-2020 normals for Mansfield, 20.4 km from Wright County, elevation 1448 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mansfield. 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 11 and the first fall freeze around October 26, a growing season of about 197 days.

Median at 36°F
last April 23, first October 16
Median at 32°F
last April 11, first October 26
Median at 28°F
last March 31, first November 4

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 8May 3Apr 30Apr 27Apr 23Apr 20Apr 17Apr 13Apr 8
32°FApr 28Apr 22Apr 17Apr 14Apr 11Apr 8Apr 4Mar 31Mar 26
28°FApr 14Apr 9Apr 6Apr 2Mar 31Mar 28Mar 24Mar 20Mar 12
24°FApr 5Mar 31Mar 27Mar 23Mar 20Mar 16Mar 12Mar 7Mar 2
20°FMar 26Mar 21Mar 16Mar 12Mar 8Mar 5Mar 2Feb 26Feb 19
16°FMar 18Mar 11Mar 6Mar 3Feb 28Feb 25Feb 20Feb 15Feb 7

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°FOct 2Oct 8Oct 11Oct 14Oct 16Oct 19Oct 21Oct 24Oct 29
32°FOct 12Oct 17Oct 21Oct 23Oct 26Oct 28Oct 31Nov 3Nov 8
28°FOct 23Oct 27Oct 31Nov 2Nov 4Nov 7Nov 10Nov 15Nov 21
24°FNov 1Nov 4Nov 8Nov 12Nov 16Nov 20Nov 25Nov 30Dec 4
20°FNov 7Nov 13Nov 18Nov 23Nov 27Dec 1Dec 4Dec 8Dec 14
16°FNov 17Nov 24Nov 29Dec 3Dec 7Dec 12Dec 17Dec 22Dec 31

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°F194187183178174170166161154
32°F218210205201197193188182175
28°F241234229224219215211206199
24°F269259252246241237231225217
20°F290280275269263257251245236
16°F312302296290284278272264256

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
4,740
Cooling degree days, base 65°F
1,272
Growing degree days, base 40°F
6,492
Growing degree days, base 45°F
5,163
Growing degree days, base 50°F
3,978
Growing degree days, base 55°F
2,934
Growing degree days, base 60°F
2,033

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,03806
February815014
March617269
April31915203
May10586449
June9245687
July1387851
August2358821
September50152553
October27126257
November602259
December913011

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 20.4 km from Wright County. 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 USC00235227 (Mansfield). Public domain.