Perryville climate

Perryville Frost Dates and Growing Season

NOAA 1991-2020 normals for Danville, 16 km from Perryville, elevation 900 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Danville. 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 9 and the first fall freeze around October 27, a growing season of about 199 days.

Median at 36°F
last April 23, first October 18
Median at 32°F
last April 9, first October 27
Median at 28°F
last March 31, first November 5

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 3Apr 30Apr 26Apr 23Apr 20Apr 16Apr 12Apr 6
32°FApr 29Apr 22Apr 18Apr 13Apr 9Apr 6Apr 3Mar 31Mar 27
28°FApr 17Apr 10Apr 5Apr 1Mar 31Mar 28Mar 24Mar 21Mar 15
24°FApr 5Mar 31Mar 28Mar 25Mar 22Mar 18Mar 14Mar 9Mar 3
20°FMar 26Mar 21Mar 17Mar 13Mar 10Mar 6Mar 2Feb 26Feb 18
16°FMar 17Mar 11Mar 6Mar 3Feb 28Feb 23Feb 17Feb 10Feb 3

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 7Oct 11Oct 14Oct 16Oct 18Oct 20Oct 23Oct 25Oct 29
32°FOct 16Oct 20Oct 23Oct 25Oct 27Oct 30Oct 31Nov 3Nov 8
28°FOct 25Oct 30Nov 1Nov 3Nov 5Nov 8Nov 11Nov 15Nov 20
24°FNov 3Nov 7Nov 10Nov 13Nov 17Nov 20Nov 24Nov 30Dec 5
20°FNov 10Nov 16Nov 21Nov 25Nov 29Dec 2Dec 6Dec 13Dec 22
16°FNov 21Nov 28Dec 2Dec 7Dec 12Dec 19Dec 24Dec 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°F196190185181178173169164159
32°F218211207203199195191184177
28°F239233227223218214210206199
24°F268259253248243237232226218
20°F294283276269263258253246238
16°F321311304298291284277269259

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
4,634
Cooling degree days, base 65°F
1,169
Growing degree days, base 40°F
6,404
Growing degree days, base 45°F
5,063
Growing degree days, base 50°F
3,876
Growing degree days, base 55°F
2,834
Growing degree days, base 60°F
1,931

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January99208
February799016
March628265
April30319215
May10395460
June10232672
July1339803
August1307770
September46150555
October28224243
November604154
December866015

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 16 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 USC00152040 (Danville). Public domain.