Red Wing climate

Red Wing Frost Dates and Growing Season

NOAA 1991-2020 normals for Red Wing Dam 3, 8 km from Red Wing, elevation 677 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Red Wing Dam 3. 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 23 and the first fall freeze around October 14, a growing season of about 173 days.

Median at 36°F
last May 4, first October 4
Median at 32°F
last April 23, first October 14
Median at 28°F
last April 12, first October 25

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 19May 13May 9May 7May 4May 2Apr 30Apr 26Apr 21
32°FMay 7May 2Apr 30Apr 27Apr 23Apr 20Apr 17Apr 14Apr 8
28°FApr 28Apr 23Apr 19Apr 16Apr 12Apr 9Apr 7Apr 4Apr 1
24°FApr 18Apr 12Apr 9Apr 6Apr 4Apr 2Mar 31Mar 27Mar 21
20°FApr 9Apr 5Apr 2Mar 31Mar 29Mar 25Mar 22Mar 19Mar 14
16°FApr 3Mar 31Mar 28Mar 24Mar 22Mar 19Mar 16Mar 12Mar 8

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 20Sep 25Sep 29Oct 1Oct 4Oct 7Oct 10Oct 13Oct 18
32°FSep 28Oct 3Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 28
28°FOct 10Oct 16Oct 19Oct 22Oct 25Oct 28Oct 31Nov 2Nov 7
24°FOct 20Oct 26Oct 30Nov 1Nov 3Nov 6Nov 9Nov 12Nov 17
20°FNov 1Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 21Nov 26
16°FNov 6Nov 10Nov 14Nov 17Nov 20Nov 23Nov 26Nov 29Dec 4

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°F171164160155152149145140134
32°F192186180176173169164158152
28°F212206202198194191186182175
24°F232224219216212209204200193
20°F247241236232228224220214207
16°F262256251247243239235229222

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
7,735
Cooling degree days, base 65°F
665
Growing degree days, base 40°F
4,646
Growing degree days, base 45°F
3,620
Growing degree days, base 50°F
2,702
Growing degree days, base 55°F
1,898
Growing degree days, base 60°F
1,215

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,56500
February1,29900
March1,04209
April583262
May24634275
June46142546
July8237694
August17177625
September14866378
October5097103
November924010
December1,34800

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 8 km from Red Wing. 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 USC00216822 (Red Wing Dam 3). Public domain.