Blanchard climate

Blanchard Frost Dates and Growing Season

NOAA 1991-2020 normals for Mooringsport 1 N, 15.2 km from Blanchard, elevation 200 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mooringsport 1 N. 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 6 and the first fall freeze around November 19, a growing season of about 257 days.

Median at 36°F
last March 21, first November 7
Median at 32°F
last March 6, first November 19
Median at 28°F
last February 21, first December 3

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 9Apr 3Mar 30Mar 25Mar 21Mar 16Mar 12Mar 7Feb 28
32°FMar 27Mar 19Mar 14Mar 10Mar 6Mar 2Feb 27Feb 22Feb 15
28°FMar 13Mar 6Mar 2Feb 27Feb 21Feb 15Feb 9Feb 2Jan 25
24°FMar 3Feb 24Feb 14Feb 8Feb 1Jan 29Jan 23Jan 15Jan 4
20°FFeb 18Feb 6Feb 1Jan 28Jan 23Jan 17Jan 11Jan 5Dec 28
16°FFeb 5Jan 31Jan 27Jan 21Jan 16Jan 11Jan 8Jan 3Dec 29

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 23Oct 29Nov 1Nov 4Nov 7Nov 10Nov 14Nov 19Nov 25
32°FNov 2Nov 7Nov 11Nov 15Nov 19Nov 24Nov 28Dec 1Dec 9
28°FNov 11Nov 18Nov 25Nov 30Dec 3Dec 7Dec 14Dec 23Dec 31
24°FNov 28Dec 4Dec 11Dec 19Dec 26Dec 31Jan 3Jan 9Jan 18
20°FDec 10Dec 22Dec 30Jan 2Jan 6Jan 10Jan 16Jan 22Feb 2
16°FDec 20Dec 31Jan 3Jan 6Jan 10Jan 14Jan 19Jan 26Feb 1

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°F255248242237231227221216208
32°F283274267262257252246239230
28°F320307300292285279272266255
24°F358346337331323314306299286
20°F365365365361353345338332320
16°F365365365365365365365355340

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
93% of years
20°F or colder
65% 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
2,323
Cooling degree days, base 65°F
2,457
Growing degree days, base 40°F
9,362
Growing degree days, base 45°F
7,700
Growing degree days, base 50°F
6,162
Growing degree days, base 55°F
4,765
Growing degree days, base 60°F
3,525

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January595269
February4275110
March26524260
April9084448
May12257710
June0441891
July05751,040
August05641,029
September2360808
October86121503
November31021210
December538383

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 15.2 km from Blanchard. 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 USC00166364 (Mooringsport 1 N). Public domain.