Clarion

... Freeze warning in effect from 3 am to 8 am EDT Saturday...

The National Weather Service in Pittsburgh has issued a freeze
warning... which is in effect from 3 am to 8 am EDT Saturday.

* Temperatures... 30 to 32.

* Impacts... unprotected outdoor plants would likely be damaged or
killed.

Precautionary/preparedness actions...

A freeze warning means sub-freezing temperatures are imminent or
highly likely.

... Frost facts for Pittsburgh area...

Normals...
average date of last killing frost in Spring April 21
average date of first killing frost in autumn October 20
average length of growing season 182 days

Records...
latest date of killing frost is Spring may 29 1894
earliest date of killing frost in autumn September 17 1959
latest date of killing frost in autumn November 11 1994

Shortest growing season 131 days may 29 1894 - Oct 7 1894

Longest growing season 215 days Apr 1 1901 - Nov 2 1901
                          215 days Apr 8 1902 - Nov 9 1902

Coldest temperatures so late in the Spring season...

    34 Jun 11 1972
    33 may 25 1925
    30 may 24 1963
    27 may 10 1966
    26 may 7 1970