Dalhart climate

Dalhart Frost Dates and Growing Season

NOAA 1991-2020 normals for Dalhart, 0.7 km from Dalhart, elevation 3984 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dalhart. 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 28 and the first fall freeze around October 20, a growing season of about 173 days.

Median at 36°F
last May 7, first October 11
Median at 32°F
last April 28, first October 20
Median at 28°F
last April 18, 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 19May 15May 11May 9May 7May 4May 2Apr 29Apr 24
32°FMay 11May 6May 3Apr 30Apr 28Apr 25Apr 22Apr 19Apr 14
28°FMay 2Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7Apr 2
24°FApr 22Apr 17Apr 13Apr 9Apr 6Apr 4Mar 31Mar 27Mar 19
20°FApr 11Apr 6Apr 2Mar 31Mar 25Mar 20Mar 15Mar 10Mar 5
16°FApr 2Mar 26Mar 19Mar 14Mar 10Mar 6Mar 3Feb 28Feb 22

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 29Oct 3Oct 6Oct 8Oct 11Oct 14Oct 16Oct 19Oct 23
32°FOct 6Oct 12Oct 15Oct 19Oct 20Oct 23Oct 25Oct 27Oct 31
28°FOct 17Oct 21Oct 24Oct 27Oct 28Oct 30Nov 1Nov 5Nov 8
24°FOct 25Oct 29Nov 1Nov 3Nov 5Nov 7Nov 10Nov 13Nov 16
20°FOct 30Nov 4Nov 7Nov 10Nov 13Nov 15Nov 18Nov 21Nov 25
16°FNov 5Nov 11Nov 15Nov 18Nov 21Nov 23Nov 26Nov 30Dec 6

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°F172166162159155152148143136
32°F190184179176173169166162155
28°F210204199195191187183178172
24°F233224220215212208204199191
20°F255248241236232227222216209
16°F279270264259254249243236228

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
4,475
Cooling degree days, base 65°F
1,368
Growing degree days, base 40°F
6,654
Growing degree days, base 45°F
5,280
Growing degree days, base 50°F
4,069
Growing degree days, base 55°F
3,023
Growing degree days, base 60°F
2,127

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January94402
February734020
March576269
April31812194
May11778430
June4286732
July0429894
August2369832
September37169583
October26122263
November591144
December89305

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 0.7 km from Dalhart. 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 USC00412238 (Dalhart). Public domain.