Wayne County climate

Wayne County Frost Dates and Growing Season

NOAA 1991-2020 normals for Hanksville, 17.3 km from Wayne County, elevation 4308 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hanksville. 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 May 5 and the first fall freeze around October 3, a growing season of about 149 days.

Median at 36°F
last May 21, first September 26
Median at 32°F
last May 5, first October 3
Median at 28°F
last April 25, first October 14

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°FJun 5Jun 1May 28May 24May 21May 17May 14May 9May 3
32°FMay 23May 17May 13May 8May 5May 2Apr 30Apr 27Apr 22
28°FMay 11May 4May 1Apr 28Apr 25Apr 22Apr 19Apr 15Apr 10
24°FApr 28Apr 22Apr 18Apr 14Apr 11Apr 8Apr 5Apr 1Mar 27
20°FApr 15Apr 10Apr 5Mar 31Mar 28Mar 22Mar 17Mar 11Mar 4
16°FApr 1Mar 25Mar 17Mar 11Mar 6Mar 1Feb 26Feb 21Feb 12

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 11Sep 16Sep 20Sep 23Sep 26Sep 28Sep 30Oct 3Oct 6
32°FSep 21Sep 25Sep 29Oct 1Oct 3Oct 5Oct 8Oct 12Oct 17
28°FOct 1Oct 4Oct 8Oct 11Oct 14Oct 17Oct 20Oct 24Oct 30
24°FOct 9Oct 14Oct 18Oct 21Oct 24Oct 28Nov 1Nov 3Nov 8
20°FOct 19Oct 23Oct 28Nov 1Nov 3Nov 6Nov 10Nov 13Nov 18
16°FOct 27Nov 3Nov 6Nov 11Nov 14Nov 17Nov 20Nov 23Nov 28

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°F146140134129125121117111102
32°F168162157153149145141134127
28°F191185179174171167163158150
24°F217209204200196191186181174
20°F248238232226221216210203195
16°F275267261256251245238232222

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
5,305
Cooling degree days, base 65°F
1,266
Growing degree days, base 40°F
6,054
Growing degree days, base 45°F
4,805
Growing degree days, base 50°F
3,710
Growing degree days, base 55°F
2,760
Growing degree days, base 60°F
1,949

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,11100
February80802
March579041
April3634142
May13161401
June13255692
July0459924
August1365829
September54117514
October3685154
November761010
December1,11700

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 17.3 km from Wayne County. 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 USW00023170 (Hanksville). Public domain.