Lockport climate

Lockport Frost Dates and Growing Season

NOAA 1991-2020 normals for Thibodaux 4 Se, 25.8 km from Lockport, elevation 15 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Thibodaux 4 Se. 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 5 and the first fall freeze around December 14, a growing season of about 311 days.

Median at 36°F
last February 27, first November 29
Median at 32°F
last February 5, first December 14
Median at 28°F
last January 23, 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 8Mar 1Feb 27Feb 22Feb 15Feb 6Jan 30
32°FMar 7Feb 27Feb 20Feb 13Feb 5Jan 31Jan 26Jan 16Jan 3
28°FFeb 21Feb 8Feb 1Jan 29Jan 23Jan 16Jan 10Jan 2Dec 24
24°FFeb 3Jan 31Jan 25Jan 19Jan 13Jan 9Jan 6Dec 31Dec 22
20°F–––––––––
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 7Nov 14Nov 19Nov 24Nov 29Dec 2Dec 6Dec 13Dec 23
32°FNov 19Nov 30Dec 4Dec 8Dec 14Dec 23Dec 31Jan 5Jan 15
28°FDec 4Dec 11Dec 21Dec 28Jan 1Jan 5Jan 10Jan 18Feb 1
24°FDec 15Dec 26Jan 1Jan 4Jan 7Jan 10Jan 15Jan 22Jan 31
20°F–––––––––
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°F311300291283277271263255245
32°F348336328319311305296286274
28°F365365365355346339332323308
24°F365365365365365365362350338
20°F365365365365365365365365365
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
96% of years
28°F or colder
75% of years
24°F or colder
36% of years
20°F or colder
9% 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
1,215
Cooling degree days, base 65°F
3,102
Growing degree days, base 40°F
11,026
Growing degree days, base 45°F
9,240
Growing degree days, base 50°F
7,517
Growing degree days, base 55°F
5,900
Growing degree days, base 60°F
4,423

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January35519195
February22535253
March12287437
April33170587
May2363826
June0505955
July05771,042
August05741,038
September0449898
October27224663
November15169379
December29831243

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 25.8 km from Lockport. 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 USC00169013 (Thibodaux 4 Se). Public domain.