Jackson climate

Jackson Frost Dates and Growing Season

NOAA 1991-2020 normals for Indian Mills 2 W, 7.4 km from Jackson, elevation 100 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Indian Mills 2 W. 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 April 28 and the first fall freeze around October 15, a growing season of about 169 days.

Median at 36°F
last May 10, first October 5
Median at 32°F
last April 28, first October 15
Median at 28°F
last April 15, first October 27

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°FMay 26May 21May 17May 13May 10May 7May 2Apr 30Apr 25
32°FMay 16May 9May 4May 1Apr 28Apr 25Apr 22Apr 19Apr 14
28°FApr 30Apr 25Apr 22Apr 19Apr 15Apr 11Apr 7Apr 3Mar 29
24°FApr 15Apr 9Apr 5Apr 3Mar 31Mar 29Mar 25Mar 21Mar 15
20°FApr 2Mar 30Mar 26Mar 22Mar 19Mar 15Mar 12Mar 6Feb 28
16°FMar 23Mar 18Mar 14Mar 9Mar 6Mar 2Feb 27Feb 23Feb 16

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°FSep 24Sep 28Oct 1Oct 3Oct 5Oct 7Oct 11Oct 14Oct 18
32°FOct 3Oct 6Oct 9Oct 13Oct 15Oct 18Oct 21Oct 25Oct 30
28°FOct 10Oct 16Oct 20Oct 23Oct 27Oct 29Nov 1Nov 4Nov 8
24°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 23
20°FNov 4Nov 9Nov 13Nov 17Nov 21Nov 25Nov 30Dec 4Dec 12
16°FNov 14Nov 21Nov 27Dec 2Dec 5Dec 10Dec 17Dec 24Dec 31

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°F168161156151147144140135129
32°F191184179173169165161156149
28°F216209204199194190186181174
24°F244235230225221216212207201
20°F273264256251245241236231224
16°F304295287281274269263257249

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
100% of years
16°F or colder
100% 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
4,940
Cooling degree days, base 65°F
989
Growing degree days, base 40°F
5,942
Growing degree days, base 45°F
4,645
Growing degree days, base 50°F
3,501
Growing degree days, base 55°F
2,515
Growing degree days, base 60°F
1,676

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00007
February84807
March717134
April38213151
May15060379
June23186614
July0328792
August3269732
September60116506
October30516212
November592155
December862013

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 7.4 km from Jackson. 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 USC00284229 (Indian Mills 2 W). Public domain.