La Plata climate

La Plata Frost Dates and Growing Season

NOAA 1991-2020 normals for Kirksville Rgnl AP, 9.3 km from La Plata, elevation 966 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kirksville Rgnl AP. 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 19 and the first fall freeze around October 18, a growing season of about 180 days.

Median at 36°F
last May 1, first October 6
Median at 32°F
last April 19, first October 18
Median at 28°F
last April 9, first October 29

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 16May 11May 7May 4May 1Apr 29Apr 25Apr 20Apr 15
32°FMay 5May 1Apr 27Apr 23Apr 19Apr 16Apr 13Apr 9Apr 5
28°FApr 25Apr 20Apr 15Apr 12Apr 9Apr 6Apr 3Mar 31Mar 25
24°FApr 15Apr 9Apr 4Apr 2Mar 31Mar 27Mar 22Mar 18Mar 13
20°FApr 5Mar 31Mar 27Mar 22Mar 19Mar 16Mar 12Mar 8Mar 2
16°FMar 27Mar 21Mar 16Mar 13Mar 9Mar 6Mar 3Feb 28Feb 21

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 19Sep 26Sep 30Oct 3Oct 6Oct 9Oct 12Oct 16Oct 20
32°FOct 1Oct 6Oct 11Oct 15Oct 18Oct 20Oct 23Oct 26Oct 31
28°FOct 15Oct 19Oct 23Oct 26Oct 29Oct 31Nov 2Nov 5Nov 9
24°FOct 26Oct 31Nov 2Nov 4Nov 6Nov 8Nov 11Nov 15Nov 20
20°FNov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 26Dec 2
16°FNov 9Nov 15Nov 18Nov 21Nov 24Nov 27Dec 1Dec 6Dec 12

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°F179171166161158153149143137
32°F200194188184180176171166157
28°F220214209205201197193188180
24°F242235229224220217212208201
20°F263254249244240236231225219
16°F281273268262258254248242234

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
5,746
Cooling degree days, base 65°F
1,009
Growing degree days, base 40°F
5,734
Growing degree days, base 45°F
4,524
Growing degree days, base 50°F
3,447
Growing degree days, base 55°F
2,501
Growing degree days, base 60°F
1,684

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,21501
February97907
March739144
April3959151
May15664382
June16214648
July2325787
August6272731
September91106468
October36418190
November719135
December1,06604

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 9.3 km from La Plata. 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 USW00014938 (Kirksville Rgnl AP). Public domain.