Ennis climate

Ennis Frost Dates and Growing Season

NOAA 1991-2020 normals for Bardwell Dam, 7.4 km from Ennis, elevation 461 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bardwell Dam. 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 8 and the first fall freeze around November 21, a growing season of about 256 days.

Median at 36°F
last March 23, first November 9
Median at 32°F
last March 8, first November 21
Median at 28°F
last February 24, first December 3

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 10Apr 4Mar 31Mar 27Mar 23Mar 18Mar 14Mar 9Mar 3
32°FApr 1Mar 24Mar 18Mar 13Mar 8Mar 5Feb 28Feb 24Feb 16
28°FMar 18Mar 10Mar 5Mar 1Feb 24Feb 17Feb 12Feb 5Jan 28
24°FMar 6Feb 28Feb 18Feb 12Feb 4Jan 30Jan 24Jan 16Jan 3
20°FFeb 26Feb 14Feb 5Jan 30Jan 22Jan 17Jan 11Jan 3Dec 23
16°FFeb 12Feb 5Jan 26Jan 20Jan 14Jan 9Jan 4Dec 30Dec 19

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 26Oct 31Nov 3Nov 6Nov 9Nov 12Nov 16Nov 21Nov 28
32°FNov 3Nov 8Nov 12Nov 16Nov 21Nov 24Nov 29Dec 3Dec 9
28°FNov 12Nov 19Nov 25Nov 30Dec 3Dec 8Dec 13Dec 20Dec 30
24°FNov 26Dec 2Dec 8Dec 15Dec 22Dec 29Jan 3Jan 12Jan 26
20°FDec 8Dec 16Dec 24Dec 31Jan 4Jan 10Jan 16Jan 25Feb 7
16°FDec 13Dec 22Dec 31Jan 3Jan 9Jan 14Jan 21Feb 1Feb 9

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°F260249243237232227222214207
32°F285276268262256250245237229
28°F320308300292286279272264253
24°F357343335327320311304295281
20°F365365365360350343335327312
16°F365365365365365365364350337

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
93% of years
20°F or colder
64% of years
16°F or colder
30% 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
2,277
Cooling degree days, base 65°F
2,586
Growing degree days, base 40°F
9,537
Growing degree days, base 45°F
7,862
Growing degree days, base 50°F
6,307
Growing degree days, base 55°F
4,902
Growing degree days, base 60°F
3,660

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January588264
February4216111
March27123256
April9582441
May13255707
June0473922
July05921,057
August06011,066
September5391837
October78135526
November28822229
December520391

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 7.4 km from Ennis. 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 USC00410518 (Bardwell Dam). Public domain.