Edwards County climate

Edwards County Frost Dates and Growing Season

NOAA 1991-2020 normals for Grayville, 16.4 km from Edwards County, elevation 435 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Grayville. 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 April 7 and the first fall freeze around October 25, a growing season of about 201 days.

Median at 36°F
last April 20, first October 17
Median at 32°F
last April 7, first October 25
Median at 28°F
last March 28, first November 5

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°FMay 6Apr 30Apr 26Apr 23Apr 20Apr 17Apr 13Apr 9Apr 5
32°FApr 23Apr 18Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 24
28°FApr 12Apr 7Apr 4Mar 31Mar 28Mar 25Mar 21Mar 17Mar 11
24°FApr 2Mar 29Mar 24Mar 19Mar 16Mar 13Mar 8Mar 3Feb 25
20°FMar 21Mar 16Mar 13Mar 9Mar 5Mar 2Feb 26Feb 21Feb 12
16°FMar 15Mar 8Mar 3Feb 28Feb 25Feb 19Feb 13Feb 8Feb 1

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 4Oct 9Oct 12Oct 14Oct 17Oct 19Oct 21Oct 23Oct 27
32°FOct 12Oct 18Oct 21Oct 23Oct 25Oct 28Oct 31Nov 2Nov 7
28°FOct 21Oct 26Oct 31Nov 2Nov 5Nov 9Nov 13Nov 17Nov 24
24°FNov 2Nov 7Nov 11Nov 15Nov 19Nov 23Nov 26Dec 1Dec 6
20°FNov 13Nov 19Nov 23Nov 27Dec 1Dec 4Dec 8Dec 13Dec 20
16°FNov 20Nov 27Dec 1Dec 6Dec 10Dec 15Dec 21Dec 26Jan 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°F199193187183178174171166158
32°F221214209205201197193188179
28°F247239233228223219214208200
24°F271263258252247242236231224
20°F294285279274269264259251242
16°F319309302297292286280273264

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
100% of years
16°F or colder
100% 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
4,584
Cooling degree days, base 65°F
1,424
Growing degree days, base 40°F
6,736
Growing degree days, base 45°F
5,402
Growing degree days, base 50°F
4,206
Growing degree days, base 55°F
3,146
Growing degree days, base 60°F
2,219

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,01007
February829010
March616580
April29127237
May79121508
June5308753
July0406871
August1348812
September36178593
October25330263
November571161
December893012

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 16.4 km from Edwards County. 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 USC00113612 (Grayville). Public domain.