Cedar Hill climate

Cedar Hill Frost Dates and Growing Season

NOAA 1991-2020 normals for Joe Pool Lake, 6 km from Cedar Hill, elevation 591 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Joe Pool Lake. 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 20 and the first fall freeze around November 13, a growing season of about 236 days.

Median at 36°F
last March 31, first November 3
Median at 32°F
last March 20, first November 13
Median at 28°F
last March 8, first November 25

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 21Apr 14Apr 7Apr 3Mar 31Mar 28Mar 24Mar 19Mar 12
32°FApr 8Apr 1Mar 29Mar 24Mar 20Mar 16Mar 12Mar 7Feb 28
28°FMar 25Mar 19Mar 15Mar 11Mar 8Mar 5Mar 1Feb 24Feb 17
24°FMar 17Mar 11Mar 6Mar 3Feb 27Feb 21Feb 14Feb 7Jan 31
20°FMar 8Mar 1Feb 20Feb 13Feb 6Jan 31Jan 28Jan 21Jan 10
16°FFeb 28Feb 12Feb 2Jan 30Jan 24Jan 20Jan 14Jan 6Dec 26

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 19Oct 24Oct 27Oct 31Nov 3Nov 6Nov 10Nov 15Nov 22
32°FOct 27Nov 1Nov 5Nov 9Nov 13Nov 17Nov 22Nov 28Dec 3
28°FNov 3Nov 9Nov 14Nov 19Nov 25Nov 29Dec 3Dec 8Dec 13
24°FNov 13Nov 21Nov 28Dec 3Dec 7Dec 12Dec 16Dec 21Dec 26
20°FNov 24Dec 3Dec 12Dec 18Dec 24Dec 28Jan 1Jan 5Jan 15
16°FDec 6Dec 16Dec 25Dec 31Jan 3Jan 7Jan 12Jan 19Jan 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°F241232225220214209203196188
32°F264255249242236231225219209
28°F289280272266261255249242231
24°F316305298291285280273266253
20°F350338331324316309302293281
16°F365365359350343337331322306

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
97% of years
16°F or colder
77% 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
2,342
Cooling degree days, base 65°F
2,591
Growing degree days, base 40°F
9,498
Growing degree days, base 45°F
7,846
Growing degree days, base 50°F
6,315
Growing degree days, base 55°F
4,921
Growing degree days, base 60°F
3,676

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January607163
February4357111
March27328266
April9488449
May14242693
June0452901
July05921,057
August06091,074
September5404849
October79139531
November29225237
December542384

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 6 km from Cedar Hill. 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 USC00414597 (Joe Pool Lake). Public domain.