The date of the last freezing temperature in spring is one of the most volatile statistics in the record book. This is because there are so many factors which can come together to make a late season cold night. It can be caused by a very cold mass of air getting displaced southward into our area. But it can also be caused by a not-so-cold mass of air on a perfectly clear and calm night if the ground is very dry.
Since the beginning of the record in 1881, the final “frost” has been as early as April 17 in 2007 and as late as June 20 in 1969. Over the past ten years, the final frost has varied from April 17 to May 27. Last year, it was May 19. Although there has been a trend of last frosts coming earlier in the year, the volatility of this particular statistic suggests that in any given year, a late frost is a possibility.
Meteorologist John Wheeler