Minot climate

Minot Frost Dates and Growing Season

NOAA 1991-2020 normals for Minot Intl AP, 3 km from Minot, elevation 1665 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Minot Intl AP. 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 10 and the first fall freeze around October 1, a growing season of about 144 days.

Median at 36°F
last May 19, first September 22
Median at 32°F
last May 10, first October 1
Median at 28°F
last April 30, first October 10

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 31May 27May 24May 22May 19May 16May 14May 11May 6
32°FMay 22May 18May 15May 13May 10May 7May 4May 1Apr 27
28°FMay 14May 9May 6May 3Apr 30Apr 28Apr 24Apr 19Apr 15
24°FMay 5Apr 30Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 5
20°FApr 25Apr 20Apr 16Apr 13Apr 10Apr 7Apr 5Apr 2Mar 29
16°FApr 17Apr 12Apr 9Apr 6Apr 4Apr 1Mar 30Mar 26Mar 19

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 11Sep 15Sep 18Sep 20Sep 22Sep 25Sep 27Sep 30Oct 4
32°FSep 19Sep 23Sep 27Sep 29Oct 1Oct 3Oct 6Oct 9Oct 14
28°FSep 27Oct 1Oct 4Oct 7Oct 10Oct 13Oct 15Oct 19Oct 23
24°FOct 6Oct 10Oct 14Oct 17Oct 20Oct 23Oct 25Oct 28Nov 1
20°FOct 13Oct 18Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 11
16°FOct 22Oct 27Oct 30Nov 1Nov 4Nov 7Nov 10Nov 14Nov 20

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°F143137133129127123120115108
32°F163157152148144140136132126
28°F183176172167163159155150142
24°F201195190185181177173169162
20°F218210206202199195189185179
16°F235229222218213209206201195

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
8,382
Cooling degree days, base 65°F
552
Growing degree days, base 40°F
4,278
Growing degree days, base 45°F
3,294
Growing degree days, base 50°F
2,425
Growing degree days, base 55°F
1,673
Growing degree days, base 60°F
1,043

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,58600
February1,33400
March1,10805
April646148
May29721232
June7490468
July16206656
August28185622
September19447320
October605270
November1,04506
December1,44900

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 3 km from Minot. 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 USW00024013 (Minot Intl AP). Public domain.