Sudan climate

Sudan Frost Dates and Growing Season

NOAA 1991-2020 normals for Muleshoe #1, 25.5 km from Sudan, elevation 3830 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Muleshoe #1. 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 April 22 and the first fall freeze around October 20, a growing season of about 180 days.

Median at 36°F
last May 2, first October 10
Median at 32°F
last April 22, first October 20
Median at 28°F
last April 12, first October 28

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 13May 9May 6May 4May 2Apr 30Apr 28Apr 25Apr 21
32°FMay 4Apr 30Apr 28Apr 24Apr 22Apr 21Apr 18Apr 15Apr 9
28°FApr 27Apr 22Apr 19Apr 16Apr 12Apr 9Apr 6Apr 2Mar 28
24°FApr 17Apr 9Apr 6Apr 3Mar 31Mar 27Mar 22Mar 18Mar 12
20°FApr 3Mar 28Mar 22Mar 18Mar 14Mar 11Mar 7Mar 3Feb 26
16°FMar 17Mar 11Mar 7Mar 4Feb 28Feb 25Feb 22Feb 16Feb 8

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 28Oct 2Oct 5Oct 8Oct 10Oct 13Oct 16Oct 19Oct 23
32°FOct 7Oct 11Oct 15Oct 17Oct 20Oct 22Oct 25Oct 28Nov 1
28°FOct 16Oct 20Oct 23Oct 26Oct 28Oct 31Nov 2Nov 5Nov 9
24°FOct 25Oct 28Nov 1Nov 3Nov 5Nov 7Nov 10Nov 13Nov 18
20°FNov 1Nov 5Nov 9Nov 11Nov 14Nov 16Nov 20Nov 23Nov 29
16°FNov 8Nov 13Nov 17Nov 21Nov 25Nov 29Dec 2Dec 6Dec 12

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°F176172168165162159155150145
32°F196191186182180177172168162
28°F217210205201197194189185178
24°F240233228223219215210205197
20°F266257252247243238233228221
16°F293284278272268263258252242

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
4,263
Cooling degree days, base 65°F
1,263
Growing degree days, base 40°F
6,645
Growing degree days, base 45°F
5,237
Growing degree days, base 50°F
3,999
Growing degree days, base 55°F
2,931
Growing degree days, base 60°F
2,022

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January88204
February689015
March534176
April2919209
May9995465
June4289735
July1376840
August2330793
September44146554
October26118257
November600047
December85705

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 25.5 km from Sudan. 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 USC00416135 (Muleshoe #1). Public domain.