Roberts County climate

Roberts County Frost Dates and Growing Season

NOAA 1991-2020 normals for Miami, 22.5 km from Roberts County, elevation 2747 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Miami. 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 16 and the first fall freeze around October 26, a growing season of about 192 days.

Median at 36°F
last April 28, first October 17
Median at 32°F
last April 16, first October 26
Median at 28°F
last April 5, first November 3

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 9May 6May 3Apr 30Apr 28Apr 24Apr 21Apr 17Apr 13
32°FMay 1Apr 27Apr 22Apr 19Apr 16Apr 13Apr 9Apr 6Apr 1
28°FApr 21Apr 15Apr 11Apr 8Apr 5Apr 2Mar 30Mar 25Mar 17
24°FApr 11Apr 5Apr 1Mar 28Mar 23Mar 18Mar 14Mar 10Mar 4
20°FMar 31Mar 23Mar 17Mar 12Mar 8Mar 5Mar 2Feb 27Feb 21
16°FMar 15Mar 9Mar 5Mar 2Feb 28Feb 24Feb 20Feb 15Feb 6

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 3Oct 7Oct 12Oct 14Oct 17Oct 20Oct 23Oct 26Oct 30
32°FOct 12Oct 17Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 7
28°FOct 20Oct 25Oct 29Nov 1Nov 3Nov 5Nov 8Nov 12Nov 17
24°FOct 28Nov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 23Nov 28
20°FNov 4Nov 10Nov 15Nov 18Nov 22Nov 26Nov 29Dec 3Dec 7
16°FNov 14Nov 20Nov 25Nov 28Dec 1Dec 5Dec 9Dec 14Dec 22

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°F190184179175171168164159152
32°F210204200196192188184179171
28°F234227221216210206201196189
24°F255248243237233227222215207
20°F278270264259254248243237226
16°F307295288282276271266259250

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
4,327
Cooling degree days, base 65°F
1,529
Growing degree days, base 40°F
6,958
Growing degree days, base 45°F
5,574
Growing degree days, base 50°F
4,337
Growing degree days, base 55°F
3,254
Growing degree days, base 60°F
2,319

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91007
February735015
March541395
April29618220
May97107478
June6311754
July1447911
August2413875
September43195603
October23933293
November576376
December88209

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 22.5 km from Roberts 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 USC00415875 (Miami). Public domain.