Mound City climate

Mound City Frost Dates and Growing Season

NOAA 1991-2020 normals for Falls City 4NE, 25.2 km from Mound City, elevation 930 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Falls City 4NE. 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 18 and the first fall freeze around October 14, a growing season of about 177 days.

Median at 36°F
last April 29, first October 4
Median at 32°F
last April 18, first October 14
Median at 28°F
last April 9, 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 11May 6May 3May 1Apr 29Apr 26Apr 23Apr 20Apr 16
32°FMay 2Apr 27Apr 24Apr 21Apr 18Apr 16Apr 13Apr 10Apr 5
28°FApr 23Apr 18Apr 15Apr 11Apr 9Apr 6Apr 4Apr 1Mar 28
24°FApr 17Apr 10Apr 6Apr 3Apr 1Mar 30Mar 26Mar 21Mar 14
20°FApr 7Apr 2Mar 30Mar 26Mar 23Mar 19Mar 14Mar 11Mar 5
16°FMar 30Mar 24Mar 19Mar 15Mar 12Mar 9Mar 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 25Sep 29Oct 1Oct 4Oct 6Oct 9Oct 12Oct 17
32°FSep 28Oct 4Oct 8Oct 11Oct 14Oct 17Oct 20Oct 23Oct 26
28°FOct 10Oct 16Oct 20Oct 23Oct 25Oct 27Oct 30Nov 1Nov 6
24°FOct 20Oct 24Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 16
20°FOct 28Nov 1Nov 5Nov 8Nov 11Nov 14Nov 17Nov 22Nov 29
16°FNov 4Nov 10Nov 14Nov 17Nov 20Nov 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°F175170165161157154150146141
32°F196190185181177174169165157
28°F217210206202197193189185178
24°F236230225220216212207203196
20°F256249244238235230226220212
16°F276269263258254250244239230

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
5,915
Cooling degree days, base 65°F
1,111
Growing degree days, base 40°F
5,825
Growing degree days, base 45°F
4,634
Growing degree days, base 50°F
3,557
Growing degree days, base 55°F
2,610
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
January1,26200
February1,01205
March768131
April4124141
May13574414
June8241683
July1367830
August4287748
September86118485
October36118190
November747030
December1,12001

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 25.2 km from Mound City. 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 USC00252851 (Falls City 4NE). Public domain.