Holton climate

Holton Frost Dates and Growing Season

NOAA 1991-2020 normals for Holton, 1.8 km from Holton, elevation 1050 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Holton. 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 24 and the first fall freeze around October 14, a growing season of about 172 days.

Median at 36°F
last May 3, first October 4
Median at 32°F
last April 24, first October 14
Median at 28°F
last April 13, first October 24

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

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 20Sep 26Sep 29Oct 1Oct 4Oct 7Oct 10Oct 13Oct 17
32°FSep 29Oct 5Oct 8Oct 11Oct 14Oct 16Oct 19Oct 22Oct 26
28°FOct 10Oct 15Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 5
24°FOct 19Oct 24Oct 27Oct 31Nov 1Nov 4Nov 6Nov 10Nov 15
20°FOct 25Nov 1Nov 4Nov 6Nov 10Nov 13Nov 17Nov 22Nov 28
16°FNov 3Nov 8Nov 14Nov 18Nov 22Nov 25Nov 29Dec 2Dec 8

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°F173166162158155151147143137
32°F191185180177172168165160153
28°F211205200196192187184179172
24°F233226221217213209204199192
20°F255246241235231226221216210
16°F275267261255251246241235227

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
5,661
Cooling degree days, base 65°F
1,146
Growing degree days, base 40°F
5,907
Growing degree days, base 45°F
4,693
Growing degree days, base 50°F
3,610
Growing degree days, base 55°F
2,656
Growing degree days, base 60°F
1,837

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,20301
February94507
March726249
April39710151
May14770394
June12231669
July1367831
August4314775
September80133505
October35919195
November710132
December1,07702

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 1.8 km from Holton. 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 USC00143759 (Holton). Public domain.