Bent County climate

Bent County Frost Dates and Growing Season

NOAA 1991-2020 normals for John Martin Dam, 17.3 km from Bent County, elevation 3814 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for John Martin Dam. 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 24 and the first fall freeze around October 15, a growing season of about 172 days.

Median at 36°F
last May 5, first October 7
Median at 32°F
last April 24, first October 15
Median at 28°F
last April 11, first October 23

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 19May 14May 11May 7May 5May 2Apr 29Apr 25Apr 20
32°FMay 8May 3Apr 30Apr 27Apr 24Apr 21Apr 17Apr 14Apr 9
28°FApr 27Apr 22Apr 18Apr 15Apr 11Apr 8Apr 4Apr 1Mar 26
24°FApr 17Apr 12Apr 7Apr 4Apr 1Mar 29Mar 25Mar 19Mar 14
20°FApr 7Apr 2Mar 29Mar 25Mar 19Mar 15Mar 11Mar 7Mar 3
16°FMar 29Mar 21Mar 15Mar 10Mar 7Mar 4Mar 2Feb 27Feb 20

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 26Sep 30Oct 2Oct 5Oct 7Oct 9Oct 12Oct 14Oct 19
32°FOct 2Oct 6Oct 10Oct 12Oct 15Oct 17Oct 20Oct 22Oct 26
28°FOct 11Oct 16Oct 19Oct 21Oct 23Oct 26Oct 28Nov 1Nov 4
24°FOct 19Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 14
20°FOct 25Oct 30Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19Nov 24
16°FOct 30Nov 5Nov 9Nov 14Nov 17Nov 21Nov 24Nov 28Dec 3

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°F171165161157154150146143137
32°F189184179175172168163159152
28°F213206201197193189185180173
24°F234226222217213209204200193
20°F257249244239234229225217209
16°F275268263259254249245238229

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
5,101
Cooling degree days, base 65°F
1,404
Growing degree days, base 40°F
6,369
Growing degree days, base 45°F
5,090
Growing degree days, base 50°F
3,963
Growing degree days, base 55°F
2,974
Growing degree days, base 60°F
2,122

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,04501
February83706
March626157
April3577170
May13384426
June12300738
July1446910
August3382843
September57170566
October32815212
November680033
December1,02302

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 17.3 km from Bent 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 USC00054388 (John Martin Dam). Public domain.