Cullen climate

Cullen Frost Dates and Growing Season

NOAA 1991-2020 normals for Benton 5E, 35.8 km from Cullen, elevation 200 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Benton 5E. 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 14 and the first fall freeze around November 14, a growing season of about 246 days.

Median at 36°F
last March 27, first November 3
Median at 32°F
last March 14, first November 14
Median at 28°F
last February 28, first November 29

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 14Apr 7Apr 3Mar 31Mar 27Mar 23Mar 19Mar 13Mar 6
32°FApr 1Mar 26Mar 21Mar 17Mar 14Mar 10Mar 5Feb 28Feb 22
28°FMar 19Mar 13Mar 8Mar 4Feb 28Feb 24Feb 17Feb 9Jan 31
24°FMar 8Mar 1Feb 24Feb 14Feb 7Feb 1Jan 28Jan 21Jan 12
20°FFeb 25Feb 10Feb 2Jan 30Jan 24Jan 20Jan 13Jan 7Dec 31
16°FFeb 7Feb 1Jan 26Jan 21Jan 17Jan 12Jan 7Jan 2Dec 25

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 21Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 14Nov 21
32°FOct 31Nov 4Nov 7Nov 10Nov 14Nov 19Nov 24Nov 30Dec 4
28°FNov 8Nov 15Nov 20Nov 25Nov 29Dec 2Dec 6Dec 13Dec 23
24°FNov 24Dec 1Dec 5Dec 12Dec 19Dec 25Jan 1Jan 6Jan 16
20°FDec 8Dec 19Dec 26Jan 1Jan 5Jan 9Jan 14Jan 20Feb 1
16°FDec 16Dec 29Jan 1Jan 5Jan 8Jan 14Jan 18Jan 24Feb 3

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°F248237231226222217212206199
32°F274265257251246240235229221
28°F309297289281273267260254243
24°F346335328320313303296286273
20°F365365358351345337332323305
16°F365365365365365365360349338

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
98% of years
20°F or colder
77% of years
16°F or colder
39% 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
2,517
Cooling degree days, base 65°F
2,322
Growing degree days, base 40°F
9,055
Growing degree days, base 45°F
7,418
Growing degree days, base 50°F
5,922
Growing degree days, base 55°F
4,567
Growing degree days, base 60°F
3,359

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January630155
February4534100
March29522239
April10574424
May19238684
June0434883
July05551,020
August05381,003
September4336783
October103100466
November33919191
December570376

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 35.8 km from Cullen. 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 USC00160718 (Benton 5E). Public domain.