Todd County climate

Todd County Frost Dates and Growing Season

NOAA 1991-2020 normals for Elkton, 3.9 km from Todd County, elevation 619 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Elkton. 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 3 and the first fall freeze around October 29, a growing season of about 207 days.

Median at 36°F
last April 15, first October 19
Median at 32°F
last April 3, first October 29
Median at 28°F
last March 25, first November 8

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 2Apr 26Apr 21Apr 18Apr 15Apr 12Apr 9Apr 5Apr 1
32°FApr 21Apr 15Apr 10Apr 7Apr 3Apr 1Mar 29Mar 24Mar 18
28°FApr 9Apr 4Mar 31Mar 29Mar 25Mar 20Mar 16Mar 12Mar 4
24°FMar 29Mar 23Mar 18Mar 15Mar 12Mar 7Mar 3Feb 28Feb 21
20°FMar 19Mar 13Mar 9Mar 3Feb 28Feb 25Feb 20Feb 14Feb 7
16°FMar 11Mar 3Feb 27Feb 22Feb 17Feb 13Feb 7Feb 2Jan 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°FOct 8Oct 13Oct 15Oct 17Oct 19Oct 22Oct 24Oct 26Oct 30
32°FOct 17Oct 21Oct 24Oct 27Oct 29Nov 1Nov 3Nov 7Nov 11
28°FOct 27Nov 1Nov 3Nov 5Nov 8Nov 11Nov 15Nov 19Nov 26
24°FNov 5Nov 9Nov 13Nov 16Nov 20Nov 24Nov 28Dec 1Dec 6
20°FNov 12Nov 18Nov 24Nov 28Dec 1Dec 4Dec 8Dec 13Dec 21
16°FNov 24Dec 1Dec 5Dec 10Dec 15Dec 20Dec 26Dec 30Jan 6

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°F205199194191186182177172165
32°F227220216212207204200194188
28°F252245240234230226221216208
24°F277269262257252248242237229
20°F305293286280275269263255247
16°F328320311305299293286279270

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
4,248
Cooling degree days, base 65°F
1,499
Growing degree days, base 40°F
7,038
Growing degree days, base 45°F
5,641
Growing degree days, base 50°F
4,383
Growing degree days, base 55°F
3,280
Growing degree days, base 60°F
2,325

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January974011
February739031
March552388
April24235276
May80134521
June4292738
July0414879
August1377841
September29201622
October23241297
November560265
December835014

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 Todd County. 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 USC00152548 (Elkton). Public domain.