Gardner climate

Gardner Frost Dates and Growing Season

NOAA 1991-2020 normals for Olathe Johnson CO AP, 4 km from Gardner, elevation 1087 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Olathe Johnson CO AP. 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 13 and the first fall freeze around October 24, a growing season of about 193 days.

Median at 36°F
last April 23, first October 15
Median at 32°F
last April 13, first October 24
Median at 28°F
last April 3, first November 2

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 6May 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 9
32°FApr 29Apr 23Apr 20Apr 17Apr 13Apr 10Apr 7Apr 4Mar 30
28°FApr 19Apr 13Apr 9Apr 6Apr 3Mar 31Mar 28Mar 23Mar 16
24°FApr 8Apr 2Mar 31Mar 27Mar 24Mar 20Mar 16Mar 10Mar 5
20°FMar 30Mar 23Mar 19Mar 16Mar 12Mar 8Mar 5Mar 1Feb 24
16°FMar 21Mar 15Mar 11Mar 7Mar 4Feb 28Feb 25Feb 21Feb 14

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

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°F192185180176173169165160152
32°F211205201197193189185180173
28°F237229223219214210206201193
24°F260251244239235230225220213
20°F278271265260255250245239231
16°F298289282277272268263258249

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
4,976
Cooling degree days, base 65°F
1,416
Growing degree days, base 40°F
6,546
Growing degree days, base 45°F
5,251
Growing degree days, base 50°F
4,091
Growing degree days, base 55°F
3,066
Growing degree days, base 60°F
2,174

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,09302
February865011
March627473
April32317201
May105102466
June7291735
July0428893
August1384848
September53161559
October29229246
November637151
December97306

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 4 km from Gardner. 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 USW00093909 (Olathe Johnson CO AP). Public domain.