Culbertson climate

Culbertson Frost Dates and Growing Season

NOAA 1991-2020 normals for Culbertson, 0.8 km from Culbertson, elevation 1940 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Culbertson. 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 21 and the first fall freeze around September 20, a growing season of about 120 days.

Median at 36°F
last May 31, first September 10
Median at 32°F
last May 21, first September 20
Median at 28°F
last May 10, first September 27

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 16Jun 10Jun 4Jun 2May 31May 28May 25May 22May 19
32°FJun 3May 29May 26May 24May 21May 18May 16May 12May 8
28°FMay 24May 19May 16May 13May 10May 7May 5May 3Apr 29
24°FMay 15May 9May 5May 3Apr 30Apr 28Apr 25Apr 21Apr 15
20°FMay 5Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 9Apr 4
16°FApr 25Apr 20Apr 15Apr 12Apr 8Apr 5Apr 2Mar 30Mar 23

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 2Sep 5Sep 7Sep 10Sep 13Sep 15Sep 18Sep 21
32°FSep 6Sep 10Sep 14Sep 17Sep 20Sep 22Sep 24Sep 26Sep 30
28°FSep 13Sep 19Sep 22Sep 25Sep 27Sep 30Oct 3Oct 6Oct 11
24°FSep 22Sep 27Sep 30Oct 3Oct 6Oct 10Oct 13Oct 16Oct 21
20°FOct 1Oct 6Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26Oct 30
16°FOct 11Oct 15Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 9

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°F11711210810410197938780
32°F137131127124120117113108102
28°F155149145142138135131126120
24°F179171164160155151148144138
20°F199193187182178173168162155
16°F220213208203199194189184177

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
8,403
Cooling degree days, base 65°F
522
Growing degree days, base 40°F
4,204
Growing degree days, base 45°F
3,219
Growing degree days, base 50°F
2,350
Growing degree days, base 55°F
1,602
Growing degree days, base 60°F
988

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,60400
February1,30600
March1,05605
April611149
May30613212
June8673439
July17206654
August31186620
September20341307
October622262
November1,08002
December1,48200

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 0.8 km from Culbertson. 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 USC00242122 (Culbertson). Public domain.