The average date of the last 32° temperature reading in the spring ranges through the month of March in most of the cultivates areas of the county, but may be as early as February 1st along the coast and as late as April 15th in the mountains. When freezes of 28° or colder are considered these dates range from January 1st along the coast to late March in the mountains.
The average date of the last 32° temperature reading in the fall is around the middle of November over most of the County, early November in the mountains, and later than December 31st along the coast. In the case of 28° readings the dates range from early December in colder spots to later than December 31st in warmer areas.
These dates give a mean growing season length, as determined by the 32° temperature readings, of 230 to 260 days in the central part of the County, as little as 200 days in the mountains, and as high as 340 days along the coast. For the 28° growing season the length ranges from 260 days in the mountains to 290 to 340 in much of the area to 365 days along the coast.