Highfill climate

Highfill Frost Dates and Growing Season

NOAA 1991-2020 normals for Fayetteville Nw Ar AP, 5.7 km from Highfill, elevation 1287 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Fayetteville Nw Ar 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 April 8 and the first fall freeze around October 28, a growing season of about 203 days.

Median at 36°F
last April 22, first October 19
Median at 32°F
last April 8, first October 28
Median at 28°F
last March 27, first November 7

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 5May 1Apr 28Apr 25Apr 22Apr 18Apr 14Apr 10Apr 3
32°FApr 26Apr 21Apr 16Apr 12Apr 8Apr 5Apr 2Mar 29Mar 21
28°FApr 12Apr 7Apr 3Mar 31Mar 27Mar 22Mar 18Mar 13Mar 6
24°FApr 2Mar 26Mar 20Mar 16Mar 13Mar 9Mar 5Feb 28Feb 22
20°FMar 21Mar 14Mar 9Mar 6Mar 3Feb 28Feb 22Feb 18Feb 11
16°FMar 12Mar 5Mar 1Feb 25Feb 20Feb 15Feb 9Feb 3Jan 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 5Oct 9Oct 13Oct 17Oct 19Oct 22Oct 25Oct 28Nov 1
32°FOct 14Oct 19Oct 23Oct 26Oct 28Oct 31Nov 2Nov 6Nov 12
28°FOct 24Oct 30Nov 1Nov 4Nov 7Nov 10Nov 15Nov 20Nov 25
24°FNov 3Nov 6Nov 10Nov 14Nov 19Nov 23Nov 27Dec 1Dec 6
20°FNov 9Nov 16Nov 23Nov 26Nov 30Dec 4Dec 8Dec 14Dec 22
16°FNov 23Nov 30Dec 4Dec 9Dec 14Dec 19Dec 24Jan 1Jan 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°F202195189185181177171165158
32°F226218213207203198194189181
28°F252244237231226221216210201
24°F277267261255249244239232223
20°F300290283278273268262255244
16°F328318310303298292286278269

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
3,858
Cooling degree days, base 65°F
1,561
Growing degree days, base 40°F
7,301
Growing degree days, base 45°F
5,845
Growing degree days, base 50°F
4,540
Growing degree days, base 55°F
3,391
Growing degree days, base 60°F
2,397

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January865016
February669136
March4836117
April23529273
May72114508
June4302748
July0446911
August1422886
September30197617
October21441311
November498394
December788022

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 5.7 km from Highfill. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00053922 (Fayetteville Nw Ar AP). Public domain.