Stutsman County climate

Stutsman County Frost Dates and Growing Season

NOAA 1991-2020 normals for Jamestown State Hosp, 23.3 km from Stutsman County, elevation 1467 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jamestown State Hosp. 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 8 and the first fall freeze around September 29, a growing season of about 143 days.

Median at 36°F
last May 17, first September 21
Median at 32°F
last May 8, first September 29
Median at 28°F
last April 30, first October 7

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 26May 22May 19May 17May 15May 12May 10May 6
32°FMay 21May 16May 13May 11May 8May 6May 3Apr 30Apr 26
28°FMay 12May 8May 4May 2Apr 30Apr 28Apr 24Apr 20Apr 16
24°FMay 3Apr 30Apr 27Apr 23Apr 20Apr 17Apr 14Apr 10Apr 5
20°FApr 25Apr 20Apr 16Apr 13Apr 10Apr 7Apr 5Apr 3Mar 28
16°FApr 16Apr 12Apr 8Apr 5Apr 3Apr 1Mar 29Mar 25Mar 17

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 10Sep 13Sep 16Sep 19Sep 21Sep 23Sep 26Sep 28Oct 1
32°FSep 17Sep 21Sep 25Sep 27Sep 29Oct 1Oct 3Oct 6Oct 11
28°FSep 26Sep 30Oct 2Oct 4Oct 7Oct 11Oct 14Oct 17Oct 21
24°FOct 4Oct 9Oct 13Oct 16Oct 19Oct 22Oct 24Oct 28Nov 1
20°FOct 15Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11
16°FOct 24Oct 29Nov 1Nov 3Nov 6Nov 9Nov 11Nov 14Nov 19

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°F142137133129126123119114108
32°F161154150146143140136132127
28°F180174169164161157153148141
24°F199193189184181176172166159
20°F219212208203200195191187179
16°F236229224219216212208203196

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
9,062
Cooling degree days, base 65°F
450
Growing degree days, base 40°F
3,965
Growing degree days, base 45°F
3,030
Growing degree days, base 50°F
2,209
Growing degree days, base 55°F
1,497
Growing degree days, base 60°F
904

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,72400
February1,43900
March1,20002
April719029
May33617204
June8086457
July19176621
August41134558
September22435282
October651254
November1,09801
December1,53100

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 23.3 km from Stutsman County. 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 USC00324418 (Jamestown State Hosp). Public domain.