Overton climate

Overton Frost Dates and Growing Season

NOAA 1991-2020 normals for Canaday Steam Plt, 14.6 km from Overton, elevation 2362 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Canaday Steam Plt. 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 26 and the first fall freeze around October 13, a growing season of about 169 days.

Median at 36°F
last May 4, first October 3
Median at 32°F
last April 26, first October 13
Median at 28°F
last April 14, first October 21

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 17May 13May 9May 7May 4May 2Apr 30Apr 28Apr 24
32°FMay 7May 3May 1Apr 29Apr 26Apr 23Apr 20Apr 17Apr 13
28°FApr 30Apr 24Apr 20Apr 17Apr 14Apr 11Apr 8Apr 4Mar 31
24°FApr 19Apr 13Apr 10Apr 7Apr 4Apr 1Mar 29Mar 24Mar 18
20°FApr 10Apr 5Apr 2Mar 30Mar 26Mar 21Mar 17Mar 13Mar 9
16°FApr 3Mar 30Mar 24Mar 19Mar 15Mar 12Mar 9Mar 5Mar 1

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 21Sep 26Sep 29Oct 1Oct 3Oct 6Oct 8Oct 11Oct 15
32°FSep 29Oct 3Oct 6Oct 9Oct 13Oct 16Oct 18Oct 21Oct 24
28°FOct 7Oct 13Oct 16Oct 19Oct 21Oct 23Oct 26Oct 30Nov 2
24°FOct 16Oct 21Oct 24Oct 27Oct 30Nov 1Nov 4Nov 8Nov 13
20°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 12Nov 17Nov 23
16°FOct 31Nov 4Nov 8Nov 12Nov 16Nov 20Nov 24Nov 28Dec 3

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°F167161157154150147144139133
32°F187180176172169164161156149
28°F209202197193188184181175169
24°F228222217212208204199194187
20°F247240234230226221216210204
16°F268260254248244240234227219

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
6,122
Cooling degree days, base 65°F
942
Growing degree days, base 40°F
5,411
Growing degree days, base 45°F
4,241
Growing degree days, base 50°F
3,214
Growing degree days, base 55°F
2,323
Growing degree days, base 60°F
1,568

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,19001
February99303
March783031
April4795105
May20550329
June28198620
July3321783
August8256713
September103104457
October4219151
November785022
December1,12501

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 14.6 km from Overton. 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 USC00251450 (Canaday Steam Plt). Public domain.