Topeka climate

Topeka Frost Dates and Growing Season

NOAA 1991-2020 normals for Topeka Muni AP, 5.2 km from Topeka, elevation 876 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Topeka Muni 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 12 and the first fall freeze around October 23, a growing season of about 191 days.

Median at 36°F
last April 25, first October 13
Median at 32°F
last April 12, first October 23
Median at 28°F
last March 31, first November 1

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

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 3Oct 8Oct 11Oct 13Oct 17Oct 19Oct 22Oct 27
32°FOct 8Oct 14Oct 19Oct 21Oct 23Oct 26Oct 28Nov 1Nov 4
28°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 10Nov 15
24°FOct 29Nov 2Nov 4Nov 7Nov 10Nov 14Nov 17Nov 22Nov 28
20°FNov 5Nov 10Nov 15Nov 18Nov 22Nov 26Nov 29Dec 2Dec 7
16°FNov 15Nov 20Nov 25Nov 29Dec 1Dec 5Dec 9Dec 14Dec 20

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°F189183178174171167163158152
32°F212206200196191187183178171
28°F236227222217212209205200192
24°F258250244239235230225219212
20°F279271265260256251246240233
16°F300291285280275270265259251

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
4,860
Cooling degree days, base 65°F
1,535
Growing degree days, base 40°F
6,721
Growing degree days, base 45°F
5,416
Growing degree days, base 50°F
4,244
Growing degree days, base 55°F
3,207
Growing degree days, base 60°F
2,303

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07901
February841012
March606579
April30922215
May96117489
June5320765
July0457922
August1399863
September51179578
October28133259
November627254
December96406

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 5.2 km from Topeka. 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 USW00013996 (Topeka Muni AP). Public domain.