Natchez climate

Natchez Frost Dates and Growing Season

NOAA 1991-2020 normals for Natchitoches, 11.8 km from Natchez, elevation 130 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Natchitoches. 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 December 1, a growing season of about 275 days.

Median at 36°F
last March 12, first November 18
Median at 32°F
last February 28, first December 1
Median at 28°F
last February 8, first December 21

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 28Mar 21Mar 17Mar 12Mar 8Mar 3Feb 28Feb 21
32°FMar 17Mar 12Mar 7Mar 3Feb 28Feb 24Feb 18Feb 11Jan 31
28°FMar 7Mar 1Feb 22Feb 15Feb 8Feb 1Jan 28Jan 19Jan 7
24°FFeb 28Feb 13Feb 4Jan 30Jan 25Jan 19Jan 11Jan 5Dec 28
20°FFeb 12Feb 6Jan 31Jan 25Jan 19Jan 10Jan 7Jan 4Jan 1
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 2Nov 6Nov 10Nov 15Nov 18Nov 21Nov 25Nov 30Dec 5
32°FNov 10Nov 16Nov 21Nov 26Dec 1Dec 4Dec 9Dec 16Dec 26
28°FNov 23Dec 1Dec 7Dec 13Dec 21Dec 27Jan 1Jan 8Jan 21
24°FDec 10Dec 23Dec 29Jan 2Jan 6Jan 10Jan 17Jan 27Feb 6
20°FDec 28Jan 2Jan 3Jan 7Jan 10Jan 19Jan 26Feb 1Feb 7
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°F273266260255249244238231222
32°F308297287281275270264257247
28°F350337328319310304297289276
24°F365365365358350341334325309
20°F365365365365365365365362342
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
97% of years
24°F or colder
68% of years
20°F or colder
23% of years
16°F or colder
3% 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
1,782
Cooling degree days, base 65°F
3,011
Growing degree days, base 40°F
10,396
Growing degree days, base 45°F
8,658
Growing degree days, base 50°F
7,024
Growing degree days, base 55°F
5,530
Growing degree days, base 60°F
4,190

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4887111
February33813153
March19053347
April61141531
May5340800
June0529979
July06371,102
August06291,094
September2437885
October52177591
November22338289
December42412143

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 11.8 km from Natchez. 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 USC00166582 (Natchitoches). Public domain.