The 1804 Hurricane season had already produced a severe hurricane with a path from Antigua to Savannah and Charleston, SC where the the storm was felt to be the worst since 1752.

In October another major hurricane moved northwestward across the Western Atlantic to north of Puerto Rico, then toward Charleston, SC. Modern reanalysis showed the storm made landfall near Atlantic City, NJ on October 9th.

Weather historian, David M Ludlum, in Early American Hurricanes, suggested that the strength of the storm was increased as it interacted with unseasonably cold air on its northwestern edge leading to a strong pressure gradient and perhaps strengthening of the system as it moved northeastward along the New England coast. This is reflected in observations from New York City where a rapid drop in pressure to 28.87 inches occurred, and the temperature plummeted from 55 to 42 degrees.

Reanalysis of the damage observed in Massachusetts suggests winds may have been as high as 110 mph. Sidney Perley, in his Historic Storms of New England wrote, "buildings and chimneys were blown down or greatly damaged.

Many churches lost spires and steeples, including the famous North Church in Boston, and few buildings escaped unscathed." Shipping was also hard hit with the schooner Hannah being swept from Cape Ann to the ledges off Cohasset. Eighteen of the crew were lost at sea with only two being saved.

As the cold air progressed south and east on the 9th, thundersnow was noted at Walpole NH as rain began to change to snow over western New England from the Connecticut hills to New Hampshire/Vermont and parts of western Massachusetts. Boston and Worcester saw no snow. Copious rain was noted eastward with Salem, MA reporting 7 inches and New Haven, CT 3.66 inches. Upwards of 48 inches of snow fell at Windsor, Vermont, while nearby Hanover NH, on the valley floor reported only 6 inches. In some places the snow remained for the entire winter. Late crops and orchard production were ruined. Snow fell until the 11th in Maine.