Mayersville climate

Mayersville Frost Dates and Growing Season

NOAA 1991-2020 normals for Rolling Fork, 15.5 km from Mayersville, elevation 105 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rolling Fork. 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 March 5 and the first fall freeze around November 20, a growing season of about 261 days.

Median at 36°F
last March 18, first November 7
Median at 32°F
last March 5, first November 20
Median at 28°F
last February 21, first December 5

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 4Mar 30Mar 26Mar 22Mar 18Mar 14Mar 11Mar 5Feb 27
32°FMar 22Mar 17Mar 13Mar 9Mar 5Mar 1Feb 25Feb 20Feb 12
28°FMar 14Mar 6Mar 2Feb 26Feb 21Feb 15Feb 8Jan 31Jan 24
24°FMar 3Feb 25Feb 15Feb 8Feb 2Jan 29Jan 23Jan 16Jan 5
20°FFeb 24Feb 10Feb 2Jan 28Jan 22Jan 16Jan 11Jan 5Dec 28
16°FFeb 15Feb 1Jan 28Jan 22Jan 17Jan 12Jan 7Jan 3Dec 27

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 25Oct 29Nov 1Nov 4Nov 7Nov 10Nov 14Nov 19Nov 25
32°FNov 3Nov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 3Dec 10
28°FNov 14Nov 20Nov 26Dec 1Dec 5Dec 11Dec 21Dec 31Jan 7
24°FNov 29Dec 6Dec 12Dec 22Dec 30Jan 3Jan 7Jan 13Jan 26
20°FDec 8Dec 20Dec 29Jan 2Jan 6Jan 11Jan 16Jan 21Feb 5
16°FDec 24Jan 1Jan 3Jan 7Jan 12Jan 17Jan 20Jan 28Feb 12

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°F261252244239235229224218210
32°F290279272265261255249243236
28°F324311303297290282276268258
24°F365348337330324316308300288
20°F365365365362354343335327313
16°F365365365365365365365356339

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
100% of years
24°F or colder
92% of years
20°F or colder
63% of years
16°F or colder
28% 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
2,297
Cooling degree days, base 65°F
2,617
Growing degree days, base 40°F
9,563
Growing degree days, base 45°F
7,903
Growing degree days, base 50°F
6,365
Growing degree days, base 55°F
4,967
Growing degree days, base 60°F
3,715

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January598475
February4347113
March26139283
April92113474
May11293747
June0478928
July05691,034
August05531,018
September4383829
October82141527
November29827228
December5179109

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 15.5 km from Mayersville. 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 USC00227560 (Rolling Fork). Public domain.