On May 19, 1780, mid-day turned to night in New England. The darkness reached as far south as New Jersey and as far north as eastern Canada. The unexplained mid-day darkness caused “intense alarm and distress” for many New Englanders. To some it was Judgment Day or the fulfillment of some prophecy from the Book of Revelation.
In May 1780, Massachusetts and the other former British colonies still were fighting against the British Empire for their independence. Four years into that conflict the success of the American Revolution still was far from certain. The British had been driven from Boston, but they occupied New York City and Savanah, Georgia. On May 12, a British army captured Charleston, South Carolina, after a six-week siege. The British also took around 5500 prisoners and 311 pieces of artillery in what was one of the worst American defeats of the War.
The earliest known report of the darkness came from Rupert, Vermont. Although the sun rose that morning, the day remained dark. In Boston the “extraordinary darkness” started around 10 a.m. and the sky was completely dark by 12:45 p.m. The darkness relented slightly that afternoon but continued throughout the day. Further east on Cape Cod, by 2:00 p.m. darkness arrived. By 5:30 p.m. it was completely dark. According to one contemporary report from goodwife Experience Richardson of Sudbury, Massachusetts, it was so dark that she could not see her hand in front of her face. In addition to the perplexing darkness, in some parts of New England ash fell from the sky. In some parts of New Hampshire, the ash could be measured in inches.
Although the darkness was unexplained, over the prior few days there had been some indications that something unusual was happening. The New England Sun appeared red, and the sky had a yellowish hue. After the day of darkness, the Moon appeared red in the night sky. Many people interpreted the darkness as an ominous religious sign. However, there is little evidence of any widespread panic.
Modern science has determined that the cause of the darkness was a combination of cloudy rainy weather and the smoke from large forest fires in Ontario and around the Great Lakes. A 2007 article from the International Journal of Wildland Fire reported that researchers from several institutions studied the rings of trees from these areas. These reflected that there had been major wildfires in 1780. Smoke from the fires was carried east in the upper atmosphere.
During the Summer of 2021, New England once again was blanketed with smoke from massive wildfires in the Western United States. That time there was no fear of it being Judgment Day and the day did not turn to night. However, the Massachusetts Department of Environmental Protection issued an air quality alert.