Morganton climate

Morganton Frost Dates and Growing Season

NOAA 1991-2020 normals for Morganton, 2 km from Morganton, elevation 1180 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Morganton. 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 28, a growing season of about 202 days.

Median at 36°F
last April 22, first October 19
Median at 32°F
last April 7, first October 28
Median at 28°F
last March 28, first November 6

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 10May 5Apr 30Apr 25Apr 22Apr 18Apr 15Apr 10Apr 5
32°FApr 26Apr 19Apr 15Apr 11Apr 7Apr 4Apr 1Mar 29Mar 24
28°FApr 13Apr 6Apr 3Mar 31Mar 28Mar 25Mar 21Mar 16Mar 9
24°FApr 1Mar 27Mar 23Mar 19Mar 14Mar 9Mar 4Feb 27Feb 20
20°FMar 21Mar 13Mar 7Mar 2Feb 26Feb 20Feb 13Feb 6Jan 30
16°FMar 9Mar 1Feb 19Feb 9Feb 4Jan 31Jan 26Jan 17Jan 6

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 7Oct 11Oct 14Oct 16Oct 19Oct 22Oct 24Oct 28Nov 1
32°FOct 14Oct 19Oct 22Oct 25Oct 28Oct 31Nov 2Nov 4Nov 9
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 10Nov 13Nov 16Nov 22
24°FNov 3Nov 8Nov 11Nov 15Nov 18Nov 23Nov 27Dec 2Dec 9
20°FNov 15Nov 21Nov 27Dec 1Dec 5Dec 9Dec 19Dec 26Jan 4
16°FDec 2Dec 8Dec 16Dec 24Dec 30Jan 3Jan 9Jan 15Jan 25

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°F200193189184179175170165158
32°F224218212207202198194188180
28°F252242236230225221216211203
24°F282272264258253247242235226
20°F321308299293286279273265255
16°F357342334329324315306299287

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
94% 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
3,802
Cooling degree days, base 65°F
1,251
Growing degree days, base 40°F
6,901
Growing degree days, base 45°F
5,432
Growing degree days, base 50°F
4,141
Growing degree days, base 55°F
3,016
Growing degree days, base 60°F
2,053

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January817011
February648021
March507295
April23719254
May7499491
June7257701
July0368832
August0323787
September31158578
October22424281
November514169
December743021

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 2 km from Morganton. 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 USC00315838 (Morganton). Public domain.