MIKE MOSS SAYS:     King,    I'm afraid we have no reliable way to forecast when the last killing frost will occur, and have to rely instead on historical data to make that kind of estimate, which carries quite a bit of uncertainty as to when the occurrence of mornings that cold are really over with in a given spring. An earlier question and answer here touched on these issues and provided some references for more information. You can read that post at

http://www.wral.com/weather/blogpost/1230944/