Fort Yates climate

Fort Yates Frost Dates and Growing Season

NOAA 1991-2020 normals for Mc Laughlin, 33.4 km from Fort Yates, elevation 2001 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mc Laughlin. 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 12 and the first fall freeze around September 28, a growing season of about 137 days.

Median at 36°F
last May 21, first September 20
Median at 32°F
last May 12, first September 28
Median at 28°F
last May 3, first October 5

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 3May 30May 26May 23May 21May 18May 15May 12May 8
32°FMay 25May 21May 18May 14May 12May 9May 7May 4May 2
28°FMay 16May 11May 8May 5May 3May 1Apr 29Apr 25Apr 19
24°FMay 8May 3Apr 30Apr 27Apr 24Apr 21Apr 17Apr 14Apr 10
20°FApr 30Apr 24Apr 19Apr 16Apr 14Apr 11Apr 8Apr 4Mar 31
16°FApr 19Apr 14Apr 11Apr 7Apr 5Apr 2Mar 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 9Sep 13Sep 16Sep 18Sep 20Sep 22Sep 25Sep 27Oct 1
32°FSep 16Sep 20Sep 23Sep 25Sep 28Sep 30Oct 2Oct 5Oct 9
28°FSep 21Sep 26Sep 29Oct 2Oct 5Oct 7Oct 10Oct 14Oct 18
24°FSep 28Oct 2Oct 6Oct 10Oct 13Oct 16Oct 19Oct 23Oct 27
20°FOct 6Oct 12Oct 15Oct 20Oct 22Oct 26Oct 29Nov 1Nov 5
16°FOct 16Oct 22Oct 26Oct 30Nov 1Nov 4Nov 7Nov 11Nov 15

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°F137131127124120116113109103
32°F155149144141137133129124118
28°F174167161157153149145141133
24°F192184180176172168163157149
20°F212204198194190186182176167
16°F230222217213208204199194185

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
8,440
Cooling degree days, base 65°F
549
Growing degree days, base 40°F
4,190
Growing degree days, base 45°F
3,222
Growing degree days, base 50°F
2,370
Growing degree days, base 55°F
1,638
Growing degree days, base 60°F
1,028

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,58600
February1,32900
March1,08106
April663141
May32717209
June7693468
July14222673
August33174606
September20842304
October634261
November1,05202
December1,44000

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 33.4 km from Fort Yates. 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 USC00395406 (Mc Laughlin). Public domain.