Epps climate

Epps Frost Dates and Growing Season

NOAA 1991-2020 normals for Rayville, 28.2 km from Epps, elevation 89 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rayville. 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 28 and the first fall freeze around November 26, a growing season of about 271 days.

Median at 36°F
last March 14, first November 12
Median at 32°F
last February 28, first November 26
Median at 28°F
last February 9, first December 11

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°FApr 2Mar 27Mar 22Mar 18Mar 14Mar 10Mar 5Mar 1Feb 24
32°FMar 19Mar 13Mar 8Mar 4Feb 28Feb 25Feb 19Feb 12Jan 31
28°FMar 8Mar 1Feb 24Feb 18Feb 9Feb 2Jan 29Jan 20Jan 10
24°FFeb 27Feb 12Feb 3Jan 30Jan 25Jan 19Jan 13Jan 6Dec 26
20°FFeb 7Feb 1Jan 26Jan 21Jan 15Jan 11Jan 6Dec 31Dec 21
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°FOct 30Nov 2Nov 5Nov 8Nov 12Nov 16Nov 20Nov 25Dec 1
32°FNov 7Nov 13Nov 17Nov 22Nov 26Nov 30Dec 3Dec 8Dec 20
28°FNov 19Nov 27Dec 1Dec 5Dec 11Dec 20Dec 28Jan 3Jan 14
24°FDec 4Dec 13Dec 21Dec 28Jan 1Jan 5Jan 10Jan 18Feb 1
20°FDec 13Dec 24Dec 30Jan 2Jan 6Jan 11Jan 16Jan 21Feb 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°F267259253248243238233228218
32°F303293284278271265260252243
28°F341329321313306299292282270
24°F365365359348341334328317304
20°F365365365365365365361347334
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
98% of years
24°F or colder
78% of years
20°F or colder
35% of years
16°F or colder
7% 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
2,060
Cooling degree days, base 65°F
2,675
Growing degree days, base 40°F
9,824
Growing degree days, base 45°F
8,129
Growing degree days, base 50°F
6,548
Growing degree days, base 55°F
5,107
Growing degree days, base 60°F
3,807

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January542696
February39411132
March23145309
April73121500
May9289746
June0472922
July05731,038
August05761,041
September4389835
October61156560
November26626244
December48212125

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 28.2 km from Epps. 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 USC00167691 (Rayville). Public domain.