The 63.62″ of precipitation which fell in 2018 in Amherst MA was the second highest calendar year total over the 183-year observational record 1836-2018, 0.82” behind the 64.44″ observed in 1888. Three of the four highest annual totals have occurred in just the past 11 years; the third highest (63.41″) in 2008 and fourth (62.57″) in 2011.
Among regional climate sites, 2018 was third wettest on record at Blue Hill Observatory in Milton MA and Providence, 5th wettest in Concord, Hartford, and Worcester, and 10th wettest in Boston.
It was particularly wet over the second half of the year. Amherst recorded 39.63″ since July 1, approximately 167% of normal, and most on record for the period. The second half of 2018 was second wettest on record at Hartford and third at Worcester.
Hartford had 22 days in 2018 with an inch or more precipitation, the most on record. Providence also had a record 22 days with an inch or more precipitation.
The recent National Climate Assessment report documented how heavy precipitation is becoming more intense and more frequent across the Northeast U.S. Precipitation falling in the heaviest 1% of events in the Northeast increased 55% from 1958 to 2016. One recent study concluded that the trend is attributable in part to an increase in southerly winds and enhanced moisture flow from the Gulf of Mexico and western Atlantic.