Pierre Part climate

Pierre Part Frost Dates and Growing Season

NOAA 1991-2020 normals for Donaldsonville 4 Sw, 20.6 km from Pierre Part, elevation 30 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Donaldsonville 4 Sw. 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 5, a growing season of about 291 days.

Median at 36°F
last March 6, first November 20
Median at 32°F
last February 21, first December 5
Median at 28°F
last February 1, first December 28

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 28Mar 20Mar 15Mar 11Mar 6Mar 2Feb 26Feb 20Feb 10
32°FMar 15Mar 8Mar 3Feb 26Feb 21Feb 14Feb 6Jan 31Jan 23
28°FMar 5Feb 25Feb 15Feb 5Feb 1Jan 28Jan 22Jan 12Dec 31
24°FFeb 24Feb 6Jan 31Jan 28Jan 22Jan 16Jan 9Jan 3Dec 26
20°FFeb 3Jan 31Jan 27Jan 22Jan 19Jan 15Jan 11Jan 7Jan 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 3Nov 8Nov 12Nov 16Nov 20Nov 24Nov 29Dec 2Dec 10
32°FNov 14Nov 22Nov 27Dec 1Dec 5Dec 9Dec 16Dec 28Jan 6
28°FDec 1Dec 6Dec 12Dec 19Dec 28Jan 2Jan 7Jan 14Jan 29
24°FDec 9Dec 21Dec 29Jan 1Jan 6Jan 11Jan 18Jan 26Feb 2
20°FDec 31Jan 2Jan 5Jan 8Jan 12Jan 16Jan 19Jan 25Feb 1
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°F291279271264259254248241231
32°F330316307298291285277267257
28°F365353342336330321311303291
24°F365365365365361351342334323
20°F365365365365365365365365348
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
88% of years
24°F or colder
55% of years
20°F or colder
19% of years
16°F or colder
5% 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
1,526
Cooling degree days, base 65°F
2,705
Growing degree days, base 40°F
10,334
Growing degree days, base 45°F
8,573
Growing degree days, base 50°F
6,896
Growing degree days, base 55°F
5,347
Growing degree days, base 60°F
3,944

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January41813156
February28321201
March16260376
April51134534
May4314775
June0462912
July0529994
August0525990
September1401850
October45182604
November20144312
December36021194

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 20.6 km from Pierre Part. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00162534 (Donaldsonville 4 Sw). Public domain.