Ayden climate

Ayden Frost Dates and Growing Season

NOAA 1991-2020 normals for Greenville, 18.6 km from Ayden, elevation 32 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Greenville. 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 27 and the first fall freeze around November 8, a growing season of about 227 days.

Median at 36°F
last April 8, first October 31
Median at 32°F
last March 27, first November 8
Median at 28°F
last March 13, first November 22

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 22Apr 17Apr 14Apr 10Apr 8Apr 5Apr 3Mar 31Mar 25
32°FApr 10Apr 5Apr 2Mar 31Mar 27Mar 23Mar 20Mar 15Mar 8
28°FMar 31Mar 25Mar 20Mar 17Mar 13Mar 9Mar 5Feb 28Feb 23
24°FMar 18Mar 11Mar 6Mar 2Feb 27Feb 23Feb 18Feb 11Feb 1
20°FMar 4Feb 25Feb 20Feb 14Feb 7Feb 1Jan 28Jan 19Jan 9
16°FFeb 19Feb 11Feb 2Jan 30Jan 26Jan 19Jan 14Jan 8Dec 30

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 18Oct 22Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 12
32°FOct 26Oct 31Nov 3Nov 5Nov 8Nov 11Nov 14Nov 19Nov 24
28°FNov 4Nov 9Nov 13Nov 18Nov 22Nov 26Nov 30Dec 4Dec 10
24°FNov 16Nov 23Nov 30Dec 3Dec 7Dec 13Dec 20Dec 29Jan 7
20°FDec 3Dec 10Dec 18Dec 24Dec 31Jan 3Jan 8Jan 16Jan 25
16°FDec 14Dec 27Jan 2Jan 6Jan 10Jan 14Jan 18Jan 25Feb 1

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°F224217213209205200197192184
32°F248240235231227223218214206
28°F278269263257252247242235229
24°F313303296289283276270264253
20°F354340332326319312305297285
16°F365365365360349342334328317

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
95% of years
16°F or colder
67% 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
2,937
Cooling degree days, base 65°F
1,916
Growing degree days, base 40°F
8,290
Growing degree days, base 45°F
6,701
Growing degree days, base 50°F
5,265
Growing degree days, base 55°F
3,985
Growing degree days, base 60°F
2,872

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January680149
February538362
March40014165
April16164362
May38182609
June2371819
July0491956
August0436901
September9268709
October13371409
November38011154
December596470

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 18.6 km from Ayden. 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 USC00313638 (Greenville). Public domain.