Throckmorton County climate

Throckmorton County Frost Dates and Growing Season

NOAA 1991-2020 normals for Throckmorton 10N, 15.2 km from Throckmorton County, elevation 1396 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Throckmorton 10N. 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 March 29 and the first fall freeze around November 7, a growing season of about 223 days.

Median at 36°F
last April 8, first October 31
Median at 32°F
last March 29, first November 7
Median at 28°F
last March 14, first November 15

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°FApr 26Apr 21Apr 16Apr 11Apr 8Apr 5Apr 2Mar 29Mar 23
32°FApr 16Apr 8Apr 4Apr 1Mar 29Mar 24Mar 20Mar 15Mar 9
28°FApr 3Mar 29Mar 23Mar 18Mar 14Mar 10Mar 7Mar 2Feb 25
24°FMar 21Mar 14Mar 10Mar 6Mar 2Feb 27Feb 22Feb 15Feb 5
20°FMar 9Mar 2Feb 27Feb 22Feb 17Feb 11Feb 5Jan 29Jan 17
16°FMar 1Feb 21Feb 14Feb 8Feb 1Jan 26Jan 17Jan 5Dec 24

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°FOct 16Oct 21Oct 24Oct 28Oct 31Nov 2Nov 5Nov 8Nov 13
32°FOct 23Oct 29Nov 1Nov 5Nov 7Nov 10Nov 13Nov 19Nov 26
28°FOct 31Nov 4Nov 8Nov 11Nov 15Nov 20Nov 25Nov 30Dec 5
24°FNov 6Nov 13Nov 18Nov 23Nov 28Dec 1Dec 6Dec 13Dec 21
20°FNov 15Nov 25Nov 30Dec 4Dec 11Dec 17Dec 23Jan 1Jan 11
16°FNov 27Dec 5Dec 13Dec 20Dec 27Jan 2Jan 7Jan 17Feb 1

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°F225217213208203199195190184
32°F250241235230223218213207200
28°F275264257251246240235228218
24°F303291282276269264258251243
20°F337323313306300293286276265
16°F365361349340334326317306294

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
99% of years
16°F or colder
86% 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
2,799
Cooling degree days, base 65°F
2,440
Growing degree days, base 40°F
8,977
Growing degree days, base 45°F
7,381
Growing degree days, base 50°F
5,918
Growing degree days, base 55°F
4,603
Growing degree days, base 60°F
3,444

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January675141
February522375
March33719212
April12581417
May23240682
June0452901
July06001,065
August05891,054
September7339782
October114107467
November36710168
December630155

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 15.2 km from Throckmorton County. 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 USC00419016 (Throckmorton 10N). Public domain.