Diamondhead climate

Diamondhead Frost Dates and Growing Season

NOAA 1991-2020 normals for Waveland, 11.3 km from Diamondhead, elevation 8 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Waveland. 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 February 21 and the first fall freeze around December 3, a growing season of about 287 days.

Median at 36°F
last March 10, first November 19
Median at 32°F
last February 21, first December 3
Median at 28°F
last February 2, first December 25

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 3Mar 26Mar 19Mar 14Mar 10Mar 5Feb 28Feb 22Feb 15
32°FMar 18Mar 11Mar 4Feb 27Feb 21Feb 16Feb 9Feb 3Jan 25
28°FMar 6Feb 24Feb 15Feb 6Feb 2Jan 29Jan 22Jan 13Dec 31
24°FFeb 21Feb 9Feb 2Jan 28Jan 23Jan 17Jan 11Jan 2Dec 25
20°FFeb 9Feb 2Jan 28Jan 21Jan 15Jan 11Jan 6Dec 31Dec 23
16°F–––––––––

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°FNov 2Nov 7Nov 11Nov 15Nov 19Nov 23Nov 28Dec 2Dec 9
32°FNov 13Nov 20Nov 26Nov 30Dec 3Dec 6Dec 13Dec 24Jan 2
28°FNov 27Dec 3Dec 8Dec 15Dec 25Dec 31Jan 5Jan 13Jan 25
24°FDec 9Dec 18Dec 26Jan 1Jan 6Jan 12Jan 18Jan 27Feb 5
20°FDec 21Dec 28Jan 2Jan 6Jan 10Jan 16Jan 22Jan 31Feb 5
16°F–––––––––

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°F286275268262255249243236224
32°F323310303295287279273264253
28°F360345335329321313305296282
24°F365365365365356348338330314
20°F365365365365365365365363345
16°F365365365365365365365365365

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
99% of years
28°F or colder
93% of years
24°F or colder
63% of years
20°F or colder
23% of years
16°F or colder
3% 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
1,705
Cooling degree days, base 65°F
2,459
Growing degree days, base 40°F
9,910
Growing degree days, base 45°F
8,157
Growing degree days, base 50°F
6,497
Growing degree days, base 55°F
4,983
Growing degree days, base 60°F
3,631

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4522121
February3216152
March19031321
April6399487
May5281741
June0436886
July0508973
August0511976
September1386835
October49164581
November22328277
December4016146

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 11.3 km from Diamondhead. 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 USC00229426 (Waveland). Public domain.