Pawnee City climate

Pawnee City Frost Dates and Growing Season

NOAA 1991-2020 normals for Table Rock 4N, 15.6 km from Pawnee City, elevation 1130 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Table Rock 4N. 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 23 and the first fall freeze around October 13, a growing season of about 172 days.

Median at 36°F
last May 3, first October 3
Median at 32°F
last April 23, first October 13
Median at 28°F
last April 12, first October 23

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 18May 12May 8May 6May 3May 1Apr 29Apr 24Apr 19
32°FMay 7May 3Apr 30Apr 26Apr 23Apr 20Apr 16Apr 12Apr 7
28°FApr 30Apr 23Apr 19Apr 15Apr 12Apr 9Apr 7Apr 3Mar 31
24°FApr 18Apr 12Apr 9Apr 6Apr 3Apr 1Mar 29Mar 24Mar 18
20°FApr 9Apr 4Mar 31Mar 29Mar 25Mar 22Mar 17Mar 12Mar 7
16°FMar 31Mar 27Mar 21Mar 17Mar 14Mar 10Mar 7Mar 3Feb 28

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 3Oct 6Oct 9Oct 12Oct 17
32°FSep 28Oct 3Oct 7Oct 10Oct 13Oct 16Oct 19Oct 22Oct 26
28°FOct 9Oct 15Oct 19Oct 21Oct 23Oct 26Oct 28Nov 1Nov 5
24°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 17
20°FOct 29Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18Nov 23Nov 29
16°FNov 5Nov 9Nov 13Nov 17Nov 21Nov 25Nov 29Dec 3Dec 10

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°F172166161157153149146140133
32°F192185180176172167163158151
28°F211205201197192188184179172
24°F234225221215211207202198190
20°F254247241236232227222217209
16°F275267262256251246240234226

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
5,916
Cooling degree days, base 65°F
1,118
Growing degree days, base 40°F
5,789
Growing degree days, base 45°F
4,598
Growing degree days, base 50°F
3,540
Growing degree days, base 55°F
2,605
Growing degree days, base 60°F
1,797

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,24300
February99705
March760246
April4268142
May16269383
June13229666
July2365827
August5301761
September87126491
October36518190
November743128
December1,11301

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 15.6 km from Pawnee City. 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 USC00258410 (Table Rock 4N). Public domain.