Jasper County climate

Jasper County Frost Dates and Growing Season

NOAA 1991-2020 normals for Newton Exp Stn, 35.6 km from Jasper County, elevation 349 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newton Exp Stn. 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 25 and the first fall freeze around November 2, a growing season of about 222 days.

Median at 36°F
last April 8, first October 25
Median at 32°F
last March 25, first November 2
Median at 28°F
last March 10, first November 15

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 24Apr 18Apr 14Apr 11Apr 8Apr 5Apr 2Mar 28Mar 20
32°FApr 12Apr 6Apr 2Mar 29Mar 25Mar 21Mar 17Mar 11Mar 4
28°FMar 28Mar 23Mar 18Mar 14Mar 10Mar 6Mar 1Feb 25Feb 17
24°FMar 19Mar 11Mar 6Mar 1Feb 26Feb 19Feb 13Feb 4Jan 27
20°FMar 7Feb 28Feb 20Feb 12Feb 4Jan 31Jan 27Jan 19Jan 9
16°FFeb 24Feb 11Feb 2Jan 30Jan 25Jan 19Jan 13Jan 6Dec 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 11Oct 16Oct 19Oct 22Oct 25Oct 27Oct 30Nov 2Nov 7
32°FOct 20Oct 24Oct 28Oct 31Nov 2Nov 5Nov 9Nov 13Nov 20
28°FOct 30Nov 3Nov 6Nov 10Nov 15Nov 19Nov 24Nov 30Dec 6
24°FNov 9Nov 15Nov 22Nov 27Dec 1Dec 4Dec 11Dec 25Jan 3
20°FNov 25Dec 1Dec 7Dec 18Dec 26Jan 1Jan 4Jan 10Jan 20
16°FDec 9Dec 20Dec 29Jan 2Jan 6Jan 11Jan 17Jan 27Feb 6

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°F221214209205200196193187179
32°F247239233227222217212206198
28°F279268262255249245239231223
24°F317304295288281275268260249
20°F357342334325318308302293280
16°F365365365361351341334326309

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
100% of years
20°F or colder
93% of years
16°F or colder
66% 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
2,469
Cooling degree days, base 65°F
2,175
Growing degree days, base 40°F
8,945
Growing degree days, base 45°F
7,293
Growing degree days, base 50°F
5,780
Growing degree days, base 55°F
4,417
Growing degree days, base 60°F
3,213

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January606371
February445699
March29022240
April11972410
May19227673
June0410859
July0504969
August0482947
September5324769
October110104465
November34515180
December532899

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 35.6 km from Jasper County. 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 USC00226308 (Newton Exp Stn). Public domain.