Frost/Freeze in Southern San Joaquin Valley, California

With persistent high pressure and the resulting much drier than normal conditions over Central Interior California, overnight minimum temperatures, with only a couple of mornings as exception, continued near and below freezing for an extended period of time through the remainder of the month of December. While minimum temperatures did drop low enough to cause concern and some protection measures among area citrus growers, only the very coldest grove locations likely needed extensive protection. Overnight minimums during the period for both the Central and Southern San Joaquin Valley ranged from the 26 to 36 degree F range. The morning of the 16th was apparently the coldest for the period of the 16th - 30th. Temperature durations up to 9 hours below freezing at the coldest locations were reported and a number of the locations dropping as low as 26 deg F.