Lafitte climate

Lafitte Frost Dates and Growing Season

NOAA 1991-2020 normals for Marrero 9 Ssw, 13.2 km from Lafitte, elevation 3 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Marrero 9 Ssw. 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 10 and the first fall freeze around December 12, a growing season of about 306 days.

Median at 36°F
last March 1, first November 26
Median at 32°F
last February 10, first December 12
Median at 28°F
last January 27, first January 1

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 21Mar 15Mar 10Mar 5Mar 1Feb 26Feb 20Feb 13Feb 5
32°FMar 10Mar 3Feb 25Feb 17Feb 10Feb 4Jan 31Jan 23Jan 9
28°FFeb 28Feb 14Feb 5Jan 31Jan 27Jan 21Jan 14Jan 6Dec 29
24°FFeb 8Feb 1Jan 28Jan 21Jan 17Jan 11Jan 6Jan 1Dec 24
20°FFeb 6Feb 1Jan 25Jan 20Jan 16Jan 12Jan 8Jan 4Dec 29
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 9Nov 15Nov 19Nov 23Nov 26Dec 1Dec 3Dec 9Dec 23
32°FNov 20Nov 28Dec 2Dec 6Dec 12Dec 20Dec 28Jan 2Jan 12
28°FDec 3Dec 11Dec 19Dec 27Jan 1Jan 4Jan 10Jan 18Feb 1
24°FDec 13Dec 25Dec 31Jan 2Jan 4Jan 10Jan 16Jan 22Feb 1
20°FDec 29Jan 2Jan 3Jan 7Jan 12Jan 16Jan 20Jan 30Feb 6
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°F305294284278272266259253244
32°F342331322313306299291284271
28°F365365356347340334326315303
24°F365365365365365364355347334
20°F365365365365365365365365360
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
97% of years
28°F or colder
76% of years
24°F or colder
42% of years
20°F or colder
14% of years
16°F or colder
2% 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
1,407
Cooling degree days, base 65°F
2,673
Growing degree days, base 40°F
10,412
Growing degree days, base 45°F
8,640
Growing degree days, base 50°F
6,941
Growing degree days, base 55°F
5,361
Growing degree days, base 60°F
3,932

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January39910162
February26120212
March14363395
April45134539
May3310772
June0453903
July0522987
August0516981
September1401850
October35183613
November18143327
December33919200

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 13.2 km from Lafitte. 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 USC00165926 (Marrero 9 Ssw). Public domain.