Evansville climate

Evansville Frost Dates and Growing Season

NOAA 1991-2020 normals for Casper 1SW, 1.6 km from Evansville, elevation 5143 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Casper 1SW. 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 12 and the first fall freeze around October 1, a growing season of about 143 days.

Median at 36°F
last May 24, first September 23
Median at 32°F
last May 12, first October 1
Median at 28°F
last April 30, first October 13

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 30May 27May 24May 22May 19May 16May 11
32°FMay 26May 22May 18May 15May 12May 9May 5May 2Apr 28
28°FMay 14May 9May 5May 2Apr 30Apr 27Apr 22Apr 18Apr 13
24°FMay 1Apr 27Apr 23Apr 19Apr 15Apr 12Apr 8Apr 3Mar 29
20°FApr 22Apr 16Apr 11Apr 7Apr 3Mar 31Mar 27Mar 21Mar 13
16°FApr 12Apr 6Apr 1Mar 28Mar 22Mar 18Mar 12Mar 8Mar 2

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 10Sep 15Sep 18Sep 21Sep 23Sep 26Sep 28Oct 1Oct 6
32°FSep 18Sep 23Sep 27Sep 30Oct 1Oct 5Oct 8Oct 13Oct 19
28°FSep 27Oct 2Oct 6Oct 10Oct 13Oct 16Oct 19Oct 23Oct 28
24°FOct 5Oct 12Oct 15Oct 18Oct 22Oct 26Oct 29Nov 2Nov 8
20°FOct 15Oct 20Oct 25Oct 29Nov 1Nov 4Nov 8Nov 12Nov 19
16°FOct 24Oct 30Nov 3Nov 6Nov 11Nov 14Nov 19Nov 23Nov 27

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°F141134130125122118114110104
32°F163156151146143139135130123
28°F186179172169165160156149142
24°F212204198193188183178173164
20°F236229223217212206201195186
16°F259249243237231227221214204

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
7,016
Cooling degree days, base 65°F
514
Growing degree days, base 40°F
4,282
Growing degree days, base 45°F
3,230
Growing degree days, base 50°F
2,345
Growing degree days, base 55°F
1,604
Growing degree days, base 60°F
984

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,18300
February1,03901
March86408
April643028
May4048146
June9361420
July5231690
August21178621
September18335322
October555292
November843016
December1,18201

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 1.6 km from Evansville. 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 USC00481572 (Casper 1SW). Public domain.