Hebbronville climate

Hebbronville Frost Dates and Growing Season

NOAA 1991-2020 normals for Hebbronville, 1.4 km from Hebbronville, elevation 580 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hebbronville. 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 4 and the first fall freeze around December 12, a growing season of about 320 days.

Median at 36°F
last February 23, first December 1
Median at 32°F
last February 4, first December 12
Median at 28°F
last January 15, first December 30

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°FMar 16Mar 8Mar 3Feb 27Feb 23Feb 17Feb 10Feb 1Jan 22
32°FMar 7Feb 28Feb 19Feb 11Feb 4Jan 28Jan 19Jan 8Dec 28
28°FFeb 28Feb 11Jan 31Jan 23Jan 15Jan 8Jan 2Dec 29Dec 18
24°FFeb 9Jan 22Jan 12Jan 7Jan 4Jan 1Dec 29Dec 23Dec 15
20°F–––––––––
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°FNov 12Nov 18Nov 23Nov 27Dec 1Dec 4Dec 9Dec 18Dec 30
32°FNov 22Nov 29Dec 3Dec 8Dec 12Dec 21Dec 30Jan 7Jan 18
28°FDec 4Dec 9Dec 17Dec 24Dec 30Jan 3Jan 9Jan 19Feb 4
24°FDec 9Dec 17Dec 23Dec 28Jan 1Jan 4Jan 7Jan 14Jan 27
20°F–––––––––
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°F322310301294285278271264253
32°F360347337328320311302291278
28°F365365365362354346339330310
24°F365365365365365365365357343
20°F365365365365365365365365365
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
95% of years
28°F or colder
68% of years
24°F or colder
29% of years
20°F or colder
7% of years
16°F or colder
0% 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
822
Cooling degree days, base 65°F
4,113
Growing degree days, base 40°F
12,423
Growing degree days, base 45°F
10,620
Growing degree days, base 50°F
8,853
Growing degree days, base 55°F
7,153
Growing degree days, base 60°F
5,563

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January25633277
February14866352
March67173575
April14308744
May1501966
June06251,075
July06761,141
August06971,162
September1514963
October11340794
November88131498
December23649306

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 1.4 km from Hebbronville. 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 USC00414058 (Hebbronville). Public domain.