December 1999 continued the recent trend toward warmer-than-normal months during the winter season in the Northeast. This was the eleventh consecutive winter month (December, January, February) that was warmer than the thirty-year mean. This December averaged 3.5 degrees warmer than normal, but 2.4 degrees cooler than December 1998. The smallest departures was noted in West Virginia, with an area-weighted state average that was 1.1 degrees warmer than normal. At the extreme opposite end of the region, meanwhile, Maine reported a state average that was 5.9 degrees warmer than normal.
Precipitation was once again well below normal for the region. On the average, the twelve-state region received only 69% of the normal December precipitation amount. Vermont reported 42% of normal, for their ninth driest December in 105 years of record. Maryland and West Virginia were the closest to normal with 81% each. This was the third consecutive dry month in the Northeast and also the third consecutive year with a drier-than-normal December.
Monthly Summary of State Temperature and Precipitation Averages.
Maximum Temperature Records (degrees F) City Date New Previous Milton, MA (tie) 5th 60 60 in 1973 Central Park, NY (tie) 5th 63 63 in 1998 Massena, NY 5th 62 54 in 1951 St. Johnsbury, VT (tie) 5th 53 53 in 1953 Providence, RI (tie) 21st 60 60 in 1957 Daily Precipitation Records (inches) City Date New Previous Harrisburg, PA 14th 1.50 1.27 in 1920