Berwick climate

Berwick Frost Dates and Growing Season

NOAA 1991-2020 normals for Morgan City, 4.3 km from Berwick, elevation 5 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Morgan City. 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 January 30 and the first fall freeze around January 1, a growing season of about 335 days.

Median at 36°F
last February 15, first December 14
Median at 32°F
last January 30, first January 1
Median at 28°F
last January 22, first January 6

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 13Mar 6Mar 1Feb 22Feb 15Feb 7Feb 1Jan 26Jan 15
32°FMar 5Feb 22Feb 9Feb 2Jan 30Jan 23Jan 18Jan 8Dec 30
28°FMar 1Feb 6Jan 31Jan 27Jan 22Jan 15Jan 7Dec 31Dec 27
24°FFeb 16Feb 1Jan 25Jan 21Jan 16Jan 11Jan 4Jan 1Dec 25
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 20Nov 30Dec 5Dec 9Dec 14Dec 22Dec 30Jan 4Jan 14
32°FDec 2Dec 12Dec 21Dec 26Jan 1Jan 4Jan 9Jan 17Feb 2
28°FDec 17Dec 26Dec 30Jan 1Jan 6Jan 10Jan 17Jan 28Feb 5
24°FDec 23Dec 29Jan 1Jan 5Jan 10Jan 14Jan 20Jan 25Feb 2
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°F337327318308302295287279268
32°F365362350343335330321310297
28°F365365365365365359348339328
24°F365365365365365365365365352
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
98% of years
32°F or colder
80% of years
28°F or colder
44% of years
24°F or colder
19% of years
20°F or colder
5% 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
1,172
Cooling degree days, base 65°F
3,064
Growing degree days, base 40°F
11,029
Growing degree days, base 45°F
9,237
Growing degree days, base 50°F
7,501
Growing degree days, base 55°F
5,871
Growing degree days, base 60°F
4,384

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January34914189
February22924239
March12468418
April29164586
May2355818
June0502952
July05701,035
August05671,032
September0464913
October19248695
November13661381
December28527243

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 4.3 km from Berwick. 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 USC00166394 (Morgan City). Public domain.