Cockrell Hill climate

Cockrell Hill Frost Dates and Growing Season

NOAA 1991-2020 normals for Dallas Redbird AP, 6.4 km from Cockrell Hill, elevation 658 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dallas Redbird AP. 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 6 and the first fall freeze around November 25, a growing season of about 265 days.

Median at 36°F
last March 19, first November 12
Median at 32°F
last March 6, first November 25
Median at 28°F
last February 22, first December 9

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 9Apr 1Mar 28Mar 23Mar 19Mar 15Mar 11Mar 6Feb 28
32°FMar 26Mar 19Mar 14Mar 10Mar 6Mar 3Feb 28Feb 23Feb 15
28°FMar 12Mar 6Mar 2Feb 27Feb 22Feb 15Feb 8Feb 1Jan 24
24°FMar 3Feb 24Feb 15Feb 7Feb 2Jan 28Jan 20Jan 12Jan 1
20°FFeb 20Feb 9Jan 31Jan 25Jan 18Jan 14Jan 6Dec 31Dec 22
16°FFeb 10Feb 1Jan 21Jan 16Jan 10Jan 5Dec 31Dec 25Dec 17

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 27Nov 1Nov 5Nov 8Nov 12Nov 16Nov 20Nov 25Dec 1
32°FNov 6Nov 12Nov 16Nov 21Nov 25Nov 29Dec 3Dec 7Dec 14
28°FNov 19Nov 26Dec 1Dec 4Dec 9Dec 13Dec 20Dec 27Jan 5
24°FDec 2Dec 8Dec 15Dec 22Dec 27Jan 2Jan 9Jan 16Feb 1
20°FDec 10Dec 18Dec 24Dec 31Jan 5Jan 11Jan 16Jan 26Feb 5
16°FDec 13Dec 21Dec 27Jan 1Jan 5Jan 10Jan 16Jan 27Feb 7

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°F260254248243238232227221211
32°F291282275270265260253247239
28°F325314305298292285280271263
24°F360348340333325318308301290
20°F365365365364356350343334319
16°F365365365365365365365360347

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
91% of years
20°F or colder
61% of years
16°F or colder
27% 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
2,093
Cooling degree days, base 65°F
2,835
Growing degree days, base 40°F
9,958
Growing degree days, base 45°F
8,266
Growing degree days, base 50°F
6,686
Growing degree days, base 55°F
5,248
Growing degree days, base 60°F
3,961

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January543489
February39410135
March23538297
April79100474
May9285741
June0501951
July06401,105
August06421,106
September2415862
October67164565
November26430254
December5006106

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 6.4 km from Cockrell 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 USW00003971 (Dallas Redbird AP). Public domain.