Frost and freezing temperatures are a major concern for growers during the spring. The last freezing temperatures of the spring season occur on average from the last few days of April in extreme southeastern sections of the state to early and mid-May over most of the Lower Peninsula to early June in interior areas of the Upper and northern Lower Michigan. Due to meteorological and local conditions, however, there can be significant variability in this date from year to year. The following is a summary of background information on frost and its prediction.