Perryville climate

Perryville Frost Dates and Growing Season

NOAA 1991-2020 normals for Perryville Wtp, 5.3 km from Perryville, elevation 502 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Perryville Wtp. 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 20, a growing season of about 182 days.

Median at 36°F
last April 30, first October 10
Median at 32°F
last April 19, first October 20
Median at 28°F
last April 5, first October 30

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

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 27Oct 1Oct 4Oct 6Oct 10Oct 12Oct 15Oct 18Oct 22
32°FOct 5Oct 10Oct 14Oct 17Oct 20Oct 22Oct 24Oct 27Oct 31
28°FOct 16Oct 21Oct 24Oct 27Oct 30Nov 1Nov 3Nov 6Nov 11
24°FOct 25Oct 31Nov 1Nov 5Nov 8Nov 11Nov 14Nov 20Nov 26
20°FNov 3Nov 8Nov 12Nov 16Nov 20Nov 25Nov 29Dec 2Dec 9
16°FNov 11Nov 17Nov 23Nov 28Dec 1Dec 5Dec 9Dec 16Dec 23

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°F180174169165161158154149143
32°F203196191186182178174168161
28°F227220214210205201196191183
24°F253244238234228223218212205
20°F277269263257253247243237227
16°F305293286280275270265258248

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
4,878
Cooling degree days, base 65°F
1,274
Growing degree days, base 40°F
6,404
Growing degree days, base 45°F
5,097
Growing degree days, base 50°F
3,938
Growing degree days, base 55°F
2,912
Growing degree days, base 60°F
2,021

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,04906
February829014
March642369
April32519205
May112101457
June10272712
July1380843
August3324786
September63145534
October29328244
November624258
December927010

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 5.3 km from Perryville. 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 USC00236641 (Perryville Wtp). Public domain.