Indianola climate

Indianola Frost Dates and Growing Season

NOAA 1991-2020 normals for Mc Cook, 16.4 km from Indianola, elevation 2602 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mc Cook. 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 May 2 and the first fall freeze around October 9, a growing season of about 159 days.

Median at 36°F
last May 11, first October 1
Median at 32°F
last May 2, first October 9
Median at 28°F
last April 21, first October 19

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 25May 19May 16May 13May 11May 9May 6May 3Apr 30
32°FMay 14May 10May 7May 4May 2Apr 30Apr 28Apr 23Apr 19
28°FMay 5May 1Apr 28Apr 24Apr 21Apr 18Apr 15Apr 12Apr 7
24°FApr 26Apr 21Apr 17Apr 14Apr 11Apr 7Apr 4Apr 1Mar 28
20°FApr 17Apr 11Apr 7Apr 5Apr 2Mar 30Mar 27Mar 22Mar 14
16°FApr 7Apr 2Mar 31Mar 26Mar 22Mar 17Mar 14Mar 9Mar 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°FSep 19Sep 23Sep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 12
32°FSep 26Oct 1Oct 4Oct 6Oct 9Oct 12Oct 14Oct 17Oct 20
28°FOct 5Oct 10Oct 14Oct 16Oct 19Oct 21Oct 23Oct 26Oct 29
24°FOct 13Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 3Nov 7
20°FOct 20Oct 26Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17
16°FOct 30Nov 3Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23Nov 27

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°F158152148145142138134130125
32°F177170166162159155151147140
28°F196190185181176173169165159
24°F216209204200196192188183176
20°F235229224219215211206201195
16°F256248243238234229225218210

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
6,021
Cooling degree days, base 65°F
1,017
Growing degree days, base 40°F
5,498
Growing degree days, base 45°F
4,323
Growing degree days, base 50°F
3,293
Growing degree days, base 55°F
2,398
Growing degree days, base 60°F
1,642

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15600
February96503
March765030
April4694110
May21046322
June28209632
July3352813
August8286742
September98112469
October4208152
November786020
December1,11301

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 16.4 km from Indianola. 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 USC00255310 (Mc Cook). Public domain.