Casey climate

Casey Frost Dates and Growing Season

NOAA 1991-2020 normals for Casey, 1.5 km from Casey, elevation 620 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Casey. 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 14 and the first fall freeze around October 20, a growing season of about 187 days.

Median at 36°F
last April 25, first October 9
Median at 32°F
last April 14, first October 20
Median at 28°F
last April 3, first October 31

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 12May 5May 2Apr 28Apr 25Apr 23Apr 20Apr 16Apr 11
32°FApr 30Apr 23Apr 20Apr 17Apr 14Apr 10Apr 8Apr 5Apr 2
28°FApr 17Apr 11Apr 7Apr 5Apr 3Apr 1Mar 30Mar 26Mar 21
24°FApr 7Apr 3Mar 31Mar 29Mar 26Mar 22Mar 19Mar 15Mar 9
20°FMar 31Mar 27Mar 23Mar 19Mar 16Mar 13Mar 10Mar 6Feb 28
16°FMar 24Mar 18Mar 14Mar 11Mar 8Mar 4Mar 1Feb 26Feb 19

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 26Oct 1Oct 4Oct 7Oct 9Oct 12Oct 15Oct 18Oct 22
32°FOct 5Oct 11Oct 14Oct 17Oct 20Oct 22Oct 24Oct 27Oct 31
28°FOct 17Oct 22Oct 26Oct 28Oct 31Nov 1Nov 3Nov 7Nov 12
24°FOct 29Nov 1Nov 4Nov 6Nov 9Nov 11Nov 14Nov 19Nov 26
20°FNov 5Nov 9Nov 12Nov 15Nov 19Nov 23Nov 27Dec 2Dec 8
16°FNov 11Nov 16Nov 22Nov 27Dec 1Dec 4Dec 9Dec 15Dec 21

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°F185177172169164160156151143
32°F205199195191187184179173166
28°F227221216211208205201196190
24°F250243238233230225221216210
20°F272264258252248243239233227
16°F295285279273267262256250242

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
5,173
Cooling degree days, base 65°F
1,228
Growing degree days, base 40°F
6,224
Growing degree days, base 45°F
4,961
Growing degree days, base 50°F
3,839
Growing degree days, base 55°F
2,850
Growing degree days, base 60°F
1,978

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13401
February91407
March694039
April34111187
May106103468
June5255700
July0363827
August1316779
September53145543
October29832238
November640347
December98603

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 1.5 km from Casey. 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 USC00111329 (Casey). Public domain.