average seasonal temperature of winter in delaware
The average length of the growing season based on minimum temperatures higher than 32 F, ranges from about 175 to 195 days. The lowest temperature of record for Delaware is -17 F, at Millsboro on January 17, 1893, came in a month which is quite likely the coldest ever known in Delaware and surrounding areas. Record Coldest year in Delaware - 1904 / Avg temperature 51.35 degrees. 2  Delaware average Summer temperature (June, July, August) - 74.2 F degrees, 16th warmest U.S. summer state. 3  Delaware average Winter temperature (December, January, February) - 36.1 F degrees, 34th coldest U.S. winter state.