Jackson climate

Jackson Frost Dates and Growing Season

NOAA 1991-2020 normals for Jackson, 3.7 km from Jackson, elevation 220 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jackson. 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 18 and the first fall freeze around November 12, a growing season of about 239 days.

Median at 36°F
last April 1, first November 1
Median at 32°F
last March 18, first November 12
Median at 28°F
last March 1, first November 25

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 20Apr 14Apr 8Apr 5Apr 1Mar 29Mar 25Mar 19Mar 11
32°FApr 6Mar 31Mar 26Mar 22Mar 18Mar 13Mar 9Mar 2Feb 25
28°FMar 21Mar 16Mar 11Mar 6Mar 1Feb 26Feb 21Feb 16Feb 4
24°FMar 11Mar 3Feb 26Feb 20Feb 13Feb 6Jan 31Jan 25Jan 10
20°FFeb 28Feb 16Feb 7Feb 1Jan 29Jan 24Jan 18Jan 9Dec 31
16°FFeb 18Feb 7Jan 31Jan 26Jan 21Jan 16Jan 9Jan 3Dec 25

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

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°F237230223219214210204199191
32°F268258251245239234228222214
28°F306292283275269263256249241
24°F341330319310304297288279266
20°F365365354344336330321310301
16°F365365365365365364352339329

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
97% of years
20°F or colder
75% of years
16°F or colder
40% 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
2,134
Cooling degree days, base 65°F
2,240
Growing degree days, base 40°F
9,303
Growing degree days, base 45°F
7,609
Growing degree days, base 50°F
6,039
Growing degree days, base 55°F
4,611
Growing degree days, base 60°F
3,339

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January534598
February3819135
March23732290
April9881435
May14234685
June0408858
July0491956
August0484949
September3341787
October90123502
November30423218
December47310127

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 3.7 km from Jackson. 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 USC00014193 (Jackson). Public domain.