Towner County climate

Towner County Frost Dates and Growing Season

NOAA 1991-2020 normals for Hansboro 4 Nne, 35.6 km from Towner County, elevation 1540 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hansboro 4 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 18 and the first fall freeze around September 23, a growing season of about 127 days.

Median at 36°F
last May 27, first September 13
Median at 32°F
last May 18, first September 23
Median at 28°F
last May 8, 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 9Jun 4Jun 1May 29May 27May 24May 21May 18May 14
32°FMay 31May 27May 24May 21May 18May 15May 13May 9May 5
28°FMay 24May 19May 15May 11May 8May 5May 3Apr 30Apr 23
24°FMay 15May 8May 4May 1Apr 29Apr 26Apr 22Apr 17Apr 12
20°FMay 5Apr 30Apr 27Apr 22Apr 18Apr 15Apr 12Apr 9Apr 4
16°FApr 25Apr 20Apr 15Apr 12Apr 9Apr 7Apr 4Apr 2Mar 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 30Sep 4Sep 8Sep 11Sep 13Sep 16Sep 19Sep 21Sep 25
32°FSep 11Sep 15Sep 19Sep 21Sep 23Sep 26Sep 28Oct 1Oct 6
28°FSep 21Sep 24Sep 27Sep 29Oct 1Oct 4Oct 6Oct 10Oct 16
24°FSep 28Oct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20Oct 25
20°FOct 5Oct 10Oct 13Oct 17Oct 20Oct 23Oct 27Oct 30Nov 2
16°FOct 13Oct 18Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 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°F1261201151111071041009586
32°F145139134131127123120115109
28°F165158153150146143138133128
24°F184178172169164160156151143
20°F203197191187183178173168162
16°F220212208204201197193188180

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
9,913
Cooling degree days, base 65°F
316
Growing degree days, base 40°F
3,569
Growing degree days, base 45°F
2,686
Growing degree days, base 50°F
1,904
Growing degree days, base 55°F
1,236
Growing degree days, base 60°F
702

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,83400
February1,55400
March1,31300
April770021
May4009157
June12061395
July39121547
August67101499
September26024242
October707143
November1,20901
December1,64300

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 35.6 km from Towner 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 USC00323963 (Hansboro 4 Nne). Public domain.