Brooks County climate

Brooks County Frost Dates and Growing Season

NOAA 1991-2020 normals for Falfurrias, 15.1 km from Brooks County, elevation 139 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Falfurrias. 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 February 25 and the first fall freeze around December 1, a growing season of about 285 days.

Median at 36°F
last March 9, first November 18
Median at 32°F
last February 25, first December 1
Median at 28°F
last January 31, first December 20

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 4Mar 27Mar 18Mar 13Mar 9Mar 5Feb 28Feb 22Feb 9
32°FMar 18Mar 11Mar 6Mar 1Feb 25Feb 17Feb 6Jan 29Jan 19
28°FMar 9Mar 1Feb 22Feb 10Jan 31Jan 23Jan 15Jan 4Dec 21
24°FMar 5Feb 20Feb 3Jan 24Jan 13Jan 6Dec 31Dec 25Dec 11
20°FMar 6Feb 16Feb 1Jan 16Jan 8Jan 5Jan 2Dec 29Dec 20
16°F–––––––––

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 31Nov 5Nov 10Nov 15Nov 18Nov 23Nov 29Dec 3Dec 12
32°FNov 12Nov 19Nov 23Nov 28Dec 1Dec 5Dec 11Dec 22Jan 1
28°FNov 24Dec 1Dec 5Dec 11Dec 20Dec 27Jan 2Jan 11Feb 1
24°FDec 4Dec 9Dec 17Dec 27Jan 1Jan 5Jan 13Jan 31Feb 20
20°FDec 14Dec 26Dec 31Jan 2Jan 5Jan 9Jan 21Feb 7Mar 4
16°F–––––––––

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°F287274266260254247241232220
32°F326310301294285277269260250
28°F365353342334326317306295282
24°F365365365365363354343333312
20°F365365365365365365365365349
16°F365365365365365365365365365

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
90% of years
24°F or colder
53% of years
20°F or colder
18% of years
16°F or colder
3% 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
999
Cooling degree days, base 65°F
3,656
Growing degree days, base 40°F
11,792
Growing degree days, base 45°F
9,994
Growing degree days, base 50°F
8,244
Growing degree days, base 55°F
6,586
Growing degree days, base 60°F
5,048

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January29830242
February18752306
March92134513
April20256686
May1445908
June05741,024
July06321,097
August06281,093
September1476925
October24277718
November120103442
December25649288

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 15.1 km from Brooks 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 USC00413063 (Falfurrias). Public domain.