Morganza climate

Morganza Frost Dates and Growing Season

NOAA 1991-2020 normals for New Roads 5 Ne, 21.7 km from Morganza, elevation 45 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for New Roads 5 Ne. 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 19 and the first fall freeze around December 5, a growing season of about 292 days.

Median at 36°F
last March 6, first November 22
Median at 32°F
last February 19, first December 5
Median at 28°F
last January 31, first December 29

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°FMar 25Mar 19Mar 14Mar 10Mar 6Mar 2Feb 26Feb 20Feb 9
32°FMar 14Mar 7Mar 1Feb 25Feb 19Feb 12Feb 5Jan 30Jan 21
28°FMar 2Feb 23Feb 14Feb 4Jan 31Jan 26Jan 20Jan 12Dec 31
24°FFeb 17Feb 6Jan 31Jan 27Jan 22Jan 15Jan 10Jan 1Dec 24
20°FFeb 12Feb 5Jan 31Jan 25Jan 17Jan 13Jan 10Jan 6Jan 2
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 5Nov 10Nov 14Nov 18Nov 22Nov 26Nov 30Dec 3Dec 9
32°FNov 15Nov 22Nov 27Dec 1Dec 5Dec 10Dec 15Dec 25Jan 4
28°FNov 28Dec 6Dec 13Dec 20Dec 29Jan 1Jan 6Jan 13Jan 27
24°FDec 13Dec 23Dec 29Jan 2Jan 8Jan 13Jan 18Jan 28Feb 6
20°FJan 1Jan 3Jan 8Jan 10Jan 13Jan 18Jan 25Feb 3Feb 10
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°F290281274268263257252245237
32°F333315306299292286278270259
28°F365355344337330321312304289
24°F365365365365362354344334322
20°F365365365365365365365365356
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
100% of years
28°F or colder
89% of years
24°F or colder
53% of years
20°F or colder
14% of years
16°F or colder
0% 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
1,522
Cooling degree days, base 65°F
2,940
Growing degree days, base 40°F
10,570
Growing degree days, base 45°F
8,807
Growing degree days, base 50°F
7,127
Growing degree days, base 55°F
5,575
Growing degree days, base 60°F
4,175

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January42910141
February29318190
March15856374
April46147551
May3343804
June0504954
July05831,048
August05771,042
September0443892
October36201630
November18945322
December36915179

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 21.7 km from Morganza. 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 USC00166686 (New Roads 5 Ne). Public domain.