Moulton climate

Moulton Frost Dates and Growing Season

NOAA 1991-2020 normals for Flatonia 4SE, 10 km from Moulton, elevation 470 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Flatonia 4SE. 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 2 and the first fall freeze around November 27, a growing season of about 271 days.

Median at 36°F
last March 13, first November 15
Median at 32°F
last March 2, first November 27
Median at 28°F
last February 16, first December 9

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

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 31Nov 4Nov 8Nov 12Nov 15Nov 19Nov 23Nov 28Dec 3
32°FNov 8Nov 14Nov 18Nov 22Nov 27Nov 30Dec 4Dec 10Dec 18
28°FNov 17Nov 24Nov 30Dec 4Dec 9Dec 15Dec 22Dec 31Jan 9
24°FNov 29Dec 6Dec 13Dec 19Dec 28Jan 3Jan 9Jan 20Feb 2
20°FDec 10Dec 17Dec 24Jan 1Jan 4Jan 10Jan 19Jan 30Feb 10
16°FDec 16Dec 27Jan 5Jan 10Jan 16Jan 24Feb 1Feb 3Feb 10

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°F274265259253247242237231221
32°F305292283277271265260254245
28°F339325315306300290283275266
24°F365359350343334326317307293
20°F365365365365365361351338324
16°F365365365365365365365365364

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
99% of years
24°F or colder
84% of years
20°F or colder
44% of years
16°F or colder
12% 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
1,635
Cooling degree days, base 65°F
2,735
Growing degree days, base 40°F
10,273
Growing degree days, base 45°F
8,530
Growing degree days, base 50°F
6,871
Growing degree days, base 55°F
5,338
Growing degree days, base 60°F
3,950

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4438135
February30415187
March18249351
April49134537
May5302763
June0459909
July05491,014
August05611,026
September2402850
October44195617
November20448320
December40213163

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 10 km from Moulton. 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 USC00413183 (Flatonia 4SE). Public domain.