Parsons climate

Parsons Frost Dates and Growing Season

NOAA 1991-2020 normals for Parsons 2 Nw, 3.9 km from Parsons, elevation 910 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Parsons 2 Nw. 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 11 and the first fall freeze around October 26, a growing season of about 196 days.

Median at 36°F
last April 22, first October 17
Median at 32°F
last April 11, first October 26
Median at 28°F
last April 1, first November 2

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 4Apr 30Apr 27Apr 25Apr 22Apr 19Apr 16Apr 12Apr 8
32°FApr 26Apr 22Apr 18Apr 15Apr 11Apr 8Apr 5Apr 1Mar 27
28°FApr 18Apr 11Apr 7Apr 4Apr 1Mar 29Mar 25Mar 18Mar 12
24°FApr 7Apr 1Mar 28Mar 24Mar 19Mar 15Mar 10Mar 6Mar 1
20°FMar 27Mar 19Mar 14Mar 9Mar 6Mar 3Feb 28Feb 24Feb 16
16°FMar 16Mar 10Mar 5Mar 2Feb 27Feb 23Feb 19Feb 13Feb 3

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

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°F196190185181177173169164159
32°F217211205201196193188183175
28°F241231225221217212207202195
24°F267257250245239234228222212
20°F288280274268262256251245235
16°F310302295289284278272265256

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
4,555
Cooling degree days, base 65°F
1,504
Growing degree days, base 40°F
6,845
Growing degree days, base 45°F
5,494
Growing degree days, base 50°F
4,288
Growing degree days, base 55°F
3,219
Growing degree days, base 60°F
2,291

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,01205
February787017
March583383
April29919220
May94104478
June6300744
July0447911
August1409873
September42186595
October25334280
November578271
December900011

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 3.9 km from Parsons. 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 USC00146242 (Parsons 2 Nw). Public domain.