Howard climate

Howard Frost Dates and Growing Season

NOAA 1991-2020 normals for Howard, 0.4 km from Howard, elevation 1570 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Howard. 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 5 and the first fall freeze around October 2, a growing season of about 149 days.

Median at 36°F
last May 14, first September 24
Median at 32°F
last May 5, first October 2
Median at 28°F
last April 27, first October 11

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

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 11Sep 16Sep 19Sep 22Sep 24Sep 27Sep 30Oct 2Oct 7
32°FSep 19Sep 23Sep 26Sep 30Oct 2Oct 4Oct 7Oct 12Oct 17
28°FSep 26Oct 1Oct 5Oct 8Oct 11Oct 15Oct 18Oct 22Oct 26
24°FOct 5Oct 11Oct 15Oct 19Oct 22Oct 24Oct 27Oct 31Nov 4
20°FOct 15Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 8Nov 13
16°FOct 25Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 22

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°F149144140136132128125121115
32°F167162157153149145141136131
28°F187180174170166162158154147
24°F206199193190185181176171163
20°F225217211207203199194189182
16°F242235230224220215210205197

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
7,456
Cooling degree days, base 65°F
776
Growing degree days, base 40°F
4,854
Growing degree days, base 45°F
3,802
Growing degree days, base 50°F
2,866
Growing degree days, base 55°F
2,049
Growing degree days, base 60°F
1,347

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,49300
February1,21701
March968013
April560273
May23841295
June38160572
July7279736
August17210659
September14279396
October5066111
November927011
December1,34400

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 0.4 km from Howard. 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 USC00394037 (Howard). Public domain.