Iuka climate

Iuka Frost Dates and Growing Season

NOAA 1991-2020 normals for Iuka, 5.4 km from Iuka, elevation 600 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Iuka. 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 9 and the first fall freeze around October 28, a growing season of about 203 days.

Median at 36°F
last April 20, first October 18
Median at 32°F
last April 9, first October 28
Median at 28°F
last March 29, first November 5

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

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

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°F201195189185182177173168161
32°F222216211207203199195189182
28°F247239233229224218214208202
24°F273266259252248243237230223
20°F308296289283275269263255247
16°F342331323315307301295285274

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
99% 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
3,641
Cooling degree days, base 65°F
1,492
Growing degree days, base 40°F
7,354
Growing degree days, base 45°F
5,876
Growing degree days, base 50°F
4,547
Growing degree days, base 55°F
3,373
Growing degree days, base 60°F
2,354

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January818022
February633035
March4718122
April22335289
May60127532
June4291736
July0395860
August1376840
September22215643
October20040326
November4855105
December724138

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 5.4 km from Iuka. 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 USC00224455 (Iuka). Public domain.