Jasper climate

Jasper Frost Dates and Growing Season

NOAA 1991-2020 normals for Dubois S In Forage Fm, 21.5 km from Jasper, elevation 690 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dubois S In Forage Fm. 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 25 and the first fall freeze around October 15, a growing season of about 172 days.

Median at 36°F
last May 6, first October 6
Median at 32°F
last April 25, first October 15
Median at 28°F
last April 13, first October 25

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 23May 17May 13May 9May 6May 3Apr 30Apr 26Apr 21
32°FMay 12May 6May 2Apr 29Apr 25Apr 22Apr 18Apr 15Apr 10
28°FMay 2Apr 25Apr 21Apr 17Apr 13Apr 10Apr 7Apr 4Apr 1
24°FApr 19Apr 12Apr 7Apr 4Apr 2Mar 31Mar 27Mar 23Mar 17
20°FApr 5Mar 31Mar 28Mar 25Mar 21Mar 18Mar 14Mar 10Mar 3
16°FMar 27Mar 21Mar 17Mar 14Mar 11Mar 6Mar 2Feb 26Feb 19

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 23Sep 28Oct 1Oct 4Oct 6Oct 8Oct 10Oct 13Oct 17
32°FOct 3Oct 7Oct 10Oct 13Oct 15Oct 18Oct 20Oct 23Oct 26
28°FOct 12Oct 17Oct 20Oct 22Oct 25Oct 27Oct 29Nov 1Nov 5
24°FOct 22Oct 27Oct 30Nov 1Nov 3Nov 5Nov 8Nov 13Nov 20
20°FNov 1Nov 4Nov 7Nov 11Nov 14Nov 18Nov 23Nov 28Dec 3
16°FNov 8Nov 14Nov 18Nov 23Nov 28Dec 1Dec 5Dec 11Dec 19

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°F170164160156152148143139132
32°F190183179176172168163158151
28°F212204200196192188183178170
24°F239229224220216211207202193
20°F262256250244239234230225218
16°F287278271265261255250245237

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
5,225
Cooling degree days, base 65°F
975
Growing degree days, base 40°F
5,929
Growing degree days, base 45°F
4,662
Growing degree days, base 50°F
3,531
Growing degree days, base 55°F
2,536
Growing degree days, base 60°F
1,683

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10306
February88909
March708253
April36214183
May13976408
June18202634
July2289752
August5254714
September73116495
October32420213
November648153
December955011

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 21.5 km from Jasper. 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 USC00122309 (Dubois S In Forage Fm). Public domain.