Jennings climate

Jennings Frost Dates and Growing Season

NOAA 1991-2020 normals for Jasper, 17.2 km from Jennings, elevation 147 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jasper. 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 11 and the first fall freeze around November 22, a growing season of about 258 days.

Median at 36°F
last March 24, first November 10
Median at 32°F
last March 11, first November 22
Median at 28°F
last February 22, first December 7

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

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 28Nov 1Nov 4Nov 7Nov 10Nov 14Nov 17Nov 21Nov 30
32°FNov 5Nov 11Nov 15Nov 18Nov 22Nov 26Dec 1Dec 7Dec 15
28°FNov 16Nov 23Nov 29Dec 2Dec 7Dec 13Dec 24Jan 2Jan 11
24°FDec 1Dec 7Dec 15Dec 26Jan 1Jan 5Jan 11Jan 20Feb 4
20°FDec 9Dec 23Jan 1Jan 6Jan 11Jan 16Jan 26Feb 1Feb 11
16°FJan 1Jan 7Jan 14Jan 18Jan 25Jan 31Feb 1Feb 6Feb 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°F260250243238233227222216205
32°F294282273265258251244238228
28°F329315306300293285277267255
24°F365353342335330320312304292
20°F365365365365361350340332322
16°F365365365365365365365365352

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
88% of years
20°F or colder
54% of years
16°F or colder
13% 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
1,722
Cooling degree days, base 65°F
2,216
Growing degree days, base 40°F
9,651
Growing degree days, base 45°F
7,901
Growing degree days, base 50°F
6,247
Growing degree days, base 55°F
4,731
Growing degree days, base 60°F
3,380

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4506131
February3219160
March21529300
April7982455
May10238693
June0390840
July0471936
August0456921
September1346795
October50148564
November21831282
December37811172

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 17.2 km from Jennings. 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 USC00084394 (Jasper). Public domain.