Comfort climate

Comfort Frost Dates and Growing Season

NOAA 1991-2020 normals for Kerrville 3 Nne, 22.9 km from Comfort, elevation 1797 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kerrville 3 Nne. 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 27 and the first fall freeze around November 7, a growing season of about 226 days.

Median at 36°F
last April 8, first October 29
Median at 32°F
last March 27, first November 7
Median at 28°F
last March 11, first November 18

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 20Apr 16Apr 12Apr 8Apr 5Apr 1Mar 29Mar 22
32°FApr 16Apr 9Apr 4Apr 1Mar 27Mar 22Mar 17Mar 11Mar 4
28°FApr 5Mar 28Mar 21Mar 15Mar 11Mar 7Mar 3Feb 26Feb 18
24°FMar 17Mar 11Mar 6Mar 3Feb 27Feb 22Feb 16Feb 8Jan 29
20°FMar 8Mar 1Feb 23Feb 16Feb 8Feb 1Jan 24Jan 15Dec 31
16°FMar 1Feb 16Feb 6Feb 1Jan 23Jan 13Jan 4Dec 28Dec 12

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 12Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 7Nov 13
32°FOct 23Oct 29Nov 1Nov 5Nov 7Nov 10Nov 14Nov 19Nov 26
28°FNov 2Nov 6Nov 10Nov 14Nov 18Nov 22Nov 26Dec 1Dec 7
24°FNov 9Nov 16Nov 21Nov 26Dec 1Dec 4Dec 9Dec 17Dec 30
20°FNov 23Nov 30Dec 6Dec 12Dec 19Dec 27Jan 1Jan 10Jan 28
16°FDec 2Dec 10Dec 20Dec 28Jan 2Jan 6Jan 16Jan 30Feb 10

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°F226217210206202197192186179
32°F253244237231226220214207199
28°F280271264258252246240232222
24°F314303293285278273265258249
20°F361344334326317308300288275
16°F365365365364354343333323305

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
92% of years
16°F or colder
61% 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
2,291
Cooling degree days, base 65°F
2,178
Growing degree days, base 40°F
9,115
Growing degree days, base 45°F
7,438
Growing degree days, base 50°F
5,887
Growing degree days, base 55°F
4,488
Growing degree days, base 60°F
3,245

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January576164
February4115113
March25824269
April9981438
May18235682
June0399849
July0487952
August0497962
September8306749
October91120501
November30220223
December528386

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 22.9 km from Comfort. 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 USC00414782 (Kerrville 3 Nne). Public domain.