The statewide average temperature during this last month of 2020 averaged 37.0°. This was 1.8° above the 1981–2010 normal and ranks as the 22nd mildest December in the 126-year record that dates back to 1895. Northern and southern portions of NJ had similar departures and rankings.
December precipitation (rain and the liquid equivalent of snow and sleet) averaged 6.24”. This includes rain measured at National Weather Service Cooperative Observing stations on the morning of December 1st but does not include rain measured at these stations for the 24 hours ending on the morning of January 1st. See an explanation of the November 30th–December 1st measurement in the November report. The monthly value is 2.39” above average and ranks as the 11th highest December precipitation total on record. North Jersey averaged 6.73”, which is 2.78” above average and ranks 7th wettest. The south came in at 5.89”, which is 2.10” above average and ranks 17th wettest. The coast averaged 6.43”, which is 2.67” above average and ranks 11th wettest.