Lenexa climate

Lenexa Frost Dates and Growing Season

NOAA 1991-2020 normals for Olathe 3E, 7.7 km from Lenexa, elevation 1055 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Olathe 3E. 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 10 and the first fall freeze around October 29, a growing season of about 202 days.

Median at 36°F
last April 19, first October 20
Median at 32°F
last April 10, first October 29
Median at 28°F
last March 31, first November 6

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 2Apr 29Apr 26Apr 22Apr 19Apr 17Apr 14Apr 10Apr 5
32°FApr 24Apr 20Apr 16Apr 13Apr 10Apr 7Apr 4Apr 1Mar 27
28°FApr 17Apr 10Apr 7Apr 3Mar 31Mar 29Mar 24Mar 20Mar 13
24°FApr 6Mar 31Mar 29Mar 24Mar 20Mar 16Mar 12Mar 8Mar 3
20°FMar 31Mar 23Mar 19Mar 14Mar 10Mar 7Mar 3Feb 28Feb 23
16°FMar 18Mar 13Mar 9Mar 5Mar 2Feb 28Feb 25Feb 20Feb 13

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 2Oct 9Oct 14Oct 17Oct 20Oct 22Oct 25Oct 27Oct 31
32°FOct 13Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 12
28°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 13Nov 17Nov 25
24°FOct 31Nov 4Nov 8Nov 12Nov 15Nov 19Nov 23Nov 28Dec 3
20°FNov 6Nov 12Nov 18Nov 22Nov 26Nov 30Dec 3Dec 7Dec 14
16°FNov 17Nov 24Nov 28Dec 2Dec 5Dec 9Dec 13Dec 18Dec 24

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°F200194189185181178173168160
32°F223215211206202198193189181
28°F246238232227223218214209201
24°F266257251246241237232226218
20°F284276269263259253248242233
16°F304295287283277273267261253

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
4,957
Cooling degree days, base 65°F
1,382
Growing degree days, base 40°F
6,551
Growing degree days, base 45°F
5,255
Growing degree days, base 50°F
4,094
Growing degree days, base 55°F
3,056
Growing degree days, base 60°F
2,150

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10502
February865010
March643169
April33116197
May9696466
June6283727
July0428893
August2369832
September48161563
October27028264
November618163
December97508

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 7.7 km from Lenexa. 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 USC00145972 (Olathe 3E). Public domain.