Bottineau County climate

Bottineau County Frost Dates and Growing Season

NOAA 1991-2020 normals for Upham 3 N, 21.2 km from Bottineau County, elevation 1425 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Upham 3 N. 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 25, a growing season of about 132 days.

Median at 36°F
last May 22, first September 15
Median at 32°F
last May 15, first September 25
Median at 28°F
last May 5, first October 1

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 2May 30May 27May 25May 22May 19May 17May 15May 11
32°FMay 26May 22May 19May 17May 15May 12May 9May 6May 3
28°FMay 18May 14May 11May 8May 5May 3Apr 30Apr 27Apr 21
24°FMay 9May 4May 1Apr 29Apr 25Apr 21Apr 18Apr 14Apr 10
20°FMay 1Apr 26Apr 21Apr 18Apr 14Apr 11Apr 8Apr 5Apr 2
16°FApr 22Apr 15Apr 11Apr 8Apr 6Apr 4Apr 2Mar 31Mar 24

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 3Sep 7Sep 10Sep 13Sep 15Sep 18Sep 21Sep 23Sep 27
32°FSep 13Sep 17Sep 20Sep 23Sep 25Sep 27Sep 29Oct 1Oct 6
28°FSep 21Sep 25Sep 27Sep 29Oct 1Oct 4Oct 7Oct 10Oct 14
24°FSep 27Oct 1Oct 4Oct 7Oct 9Oct 12Oct 15Oct 19Oct 23
20°FOct 4Oct 9Oct 13Oct 16Oct 18Oct 21Oct 24Oct 27Nov 1
16°FOct 13Oct 18Oct 22Oct 24Oct 27Oct 30Nov 2Nov 5Nov 10

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°F132127123119116113109106100
32°F148143139135132129125121115
28°F166161156153149145142137131
24°F185179174170166162158153148
20°F206199193189185180176170164
16°F222215210205201197193187179

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
9,635
Cooling degree days, base 65°F
369
Growing degree days, base 40°F
3,732
Growing degree days, base 45°F
2,827
Growing degree days, base 50°F
2,028
Growing degree days, base 55°F
1,343
Growing degree days, base 60°F
782

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,81200
February1,50800
March1,26201
April725131
May34914193
June10169421
July31144578
August56118527
September26923237
October716139
November1,17901
December1,62900

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 21.2 km from Bottineau 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 USC00328913 (Upham 3 N). Public domain.