Balmorhea climate

Balmorhea Frost Dates and Growing Season

NOAA 1991-2020 normals for Balmorhea, 0.5 km from Balmorhea, elevation 3220 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Balmorhea. 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 9, a growing season of about 228 days.

Median at 36°F
last April 10, first October 31
Median at 32°F
last March 29, first November 9
Median at 28°F
last March 8, first November 19

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 29Apr 22Apr 17Apr 14Apr 10Apr 7Apr 4Apr 1Mar 25
32°FApr 16Apr 8Apr 4Apr 1Mar 29Mar 23Mar 17Mar 12Mar 6
28°FMar 31Mar 22Mar 16Mar 12Mar 8Mar 5Mar 2Feb 26Feb 18
24°FMar 12Mar 7Mar 3Feb 28Feb 23Feb 17Feb 11Feb 5Jan 27
20°FMar 1Feb 20Feb 12Feb 5Jan 31Jan 25Jan 18Jan 10Dec 30
16°FFeb 14Feb 2Jan 27Jan 21Jan 15Jan 10Jan 3Dec 26Dec 15

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 17Oct 21Oct 25Oct 28Oct 31Nov 2Nov 5Nov 7Nov 12
32°FOct 27Nov 1Nov 3Nov 6Nov 9Nov 11Nov 14Nov 18Nov 22
28°FNov 5Nov 9Nov 13Nov 16Nov 19Nov 22Nov 25Nov 30Dec 4
24°FNov 14Nov 21Nov 25Nov 28Dec 1Dec 5Dec 9Dec 14Dec 21
20°FNov 25Dec 2Dec 8Dec 14Dec 19Dec 24Dec 29Jan 4Jan 15
16°FDec 4Dec 14Dec 21Dec 27Jan 1Jan 4Jan 10Jan 17Jan 30

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°F226217211207202198193188181
32°F253245239233228221216209200
28°F279270264259254248243237230
24°F312301293288282276271265256
20°F355344335329321314306297283
16°F365365365365356348341332319

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
95% 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
2,494
Cooling degree days, base 65°F
2,123
Growing degree days, base 40°F
8,884
Growing degree days, base 45°F
7,229
Growing degree days, base 50°F
5,704
Growing degree days, base 55°F
4,337
Growing degree days, base 60°F
3,141

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January600056
February4273100
March28119243
April11077424
May24258700
June0459909
July0487952
August0460925
September14264701
October10387458
November3499175
December586161

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 0.5 km from Balmorhea. 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 USC00410498 (Balmorhea). Public domain.