On Friday, May 19, 1780, the sky grew dark as high noon approached. From New Jersey to
Maine (USA), people looked skyward as the world changed into a brassy color. It was
Friday, the day of Christ’s crucifixion, during a low time for the colonists in the
American Revolution. By midafternoon, however, the sky had brightened a little, and
business resumed as usual. As older citizens of New England pondered this, a few
remembered other occasions when the sky grew dark at noon, including an instance in
ovember of 1716.
A few clues point to the cause of this natural phenomenon. Rainfall in roughly the
same period of time contained soot and bits of burnt leaves. Scientists thought the
darknesses might be caused by huge forest fires burning uncontrolled in the wild
This theory was later proven to be correct. In addition, the usual west-to-east wind
flow and weather made the New England area particularly susceptible to such periods of
darkness. It turns out that the soot and smoke from western fires were carried high into
the atmosphere and drawn into developing storm systems. There they hovered, hidden
above lower clouds. Many such storm systems make their way down the St. Lawrence Valley
and on to the ocean, so dark skies often occurred around southern Canada and New England.
These periods of darkness at noon were recorded eighteen times between 1706 and 1910.
They no longer occur today because of deforestation and improved fire prevention efforts.