A temperature of 32 degrees Fahrenheit has officially been recorded
as late as May 25th in Cincinnati, May 16th at Columbus and May
21st at Dayton. However, elements such as topography, urban or
rural setting and placement of the recording instrument can create
wide variations in temperatures across an area.

National Weather Service temperatures are officially taken at an
elevation of five feet above the ground, but the temperature at
ground level may be colder. On typical spring nights when frost
occurs, the temperatures at the five foot level may read 36 degrees
while at ground level it is actually the 32 degrees needed to form
frost.

The following reference table will give an idea as to when the last
freezing temperatures might occur, based on the last 30 years of
climatological data (1991 to 2020) at each of the listed locations.


Location          Avg date      Last 32F in one    Last 32F in nine
                  last 32F      year out of ten    years out of ten
                  in Spring     (10% probability)  (90% probability)

..Southwest Ohio
Cincinnati (KLUK)  Apr 16            Apr 2              May 3
Hamilton (KHAO)    Apr 22            Apr 6              May 10
Milford            Apr 23            Apr 9              May 8
Wilmington         Apr 17            Apr 3              May 4

..Central Ohio
Circleville        Apr 17            Apr 2              May 4
Columbus (KCMH)    Apr 18            Apr 4              May 5
Lancaster          Apr 22            Apr 7              May 9
Logan              Apr 30            Apr 18             May 17
Marysville         Apr 19            Apr 5              May 5
Newark             Apr 22            Apr 6              May 10
Washington CH      Apr 23            Apr 10             May 8

..Miami Valley
Bellefontaine      Apr 26            Apr 12             May 12
Celina             Apr 27            Apr 12             May 10
Dayton (KDAY)      Apr 16            Apr 2              May 3
Eaton              Apr 21            Apr 7              May 7
Greenville         Apr 23            Apr 9              May 7
Kenton             Apr 22            Apr 9              May 7
Springfield        Apr 25            Apr 12             May 12
Xenia              Apr 18            Apr 3              May 4

..South Central Ohio
Chillicothe        Apr 20            Apr 6              May 7
Hillsboro          Apr 24            Apr 10             May 11
Portsmouth         Apr 17            Apr 3              May 5

..Kentucky
Covington (KCVG)   Apr 18            Apr 3              May 7
Maysville          Apr 18            Apr 4              May 3
Warsaw             Apr 17            Apr 2              May 4
Williamston        Apr 11            Mar 28             Apr 30

..Indiana
Brookville         Apr 20            Apr 16             May 7
Milan              Apr 28            Apr 13             May 16
Richmond           Apr 24            Apr 8              May 10
Vevay              Apr 9             Mar 26             Apr 25



Frost/freeze headlines have been initiated for the entire forecast area.