Audubon climate

Audubon Frost Dates and Growing Season

NOAA 1991-2020 normals for Detroit Lakes 1 Nne, 11.4 km from Audubon, elevation 1355 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Detroit Lakes 1 Nne. 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 15 and the first fall freeze around September 24, a growing season of about 130 days.

Median at 36°F
last May 26, first September 13
Median at 32°F
last May 15, first September 24
Median at 28°F
last May 5, first October 3

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°FJun 7Jun 3May 31May 29May 26May 24May 20May 17May 12
32°FMay 30May 26May 22May 18May 15May 12May 9May 6May 2
28°FMay 19May 13May 10May 8May 5May 3May 1Apr 28Apr 24
24°FMay 9May 4May 1Apr 29Apr 26Apr 23Apr 21Apr 17Apr 13
20°FMay 1Apr 27Apr 23Apr 21Apr 18Apr 15Apr 12Apr 9Apr 4
16°FApr 24Apr 20Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1Mar 27

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°FAug 28Sep 3Sep 6Sep 10Sep 13Sep 16Sep 19Sep 22Sep 27
32°FSep 9Sep 14Sep 18Sep 21Sep 24Sep 26Sep 30Oct 2Oct 6
28°FSep 18Sep 24Sep 27Oct 1Oct 3Oct 5Oct 8Oct 12Oct 18
24°FSep 29Oct 3Oct 6Oct 10Oct 14Oct 17Oct 21Oct 25Oct 29
20°FOct 7Oct 13Oct 18Oct 21Oct 25Oct 28Oct 31Nov 3Nov 8
16°FOct 19Oct 26Oct 30Nov 1Nov 3Nov 6Nov 8Nov 12Nov 18

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°F1271211171121091061019687
32°F150143138135130126122117111
28°F168162158154150146142138131
24°F189182177172169165161156148
20°F210202197193189184180175169
16°F227220214210206203199193185

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
9,397
Cooling degree days, base 65°F
357
Growing degree days, base 40°F
3,783
Growing degree days, base 45°F
2,865
Growing degree days, base 50°F
2,049
Growing degree days, base 55°F
1,350
Growing degree days, base 60°F
774

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,80400
February1,49900
March1,22603
April734133
May34516195
June9170431
July32136569
August58104512
September24229263
October674144
November1,11201
December1,58100

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 11.4 km from Audubon. 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 USC00212142 (Detroit Lakes 1 Nne). Public domain.