Summer 2016 was the warmest summer season since world-wide records began in 1880. The hottest three month spell ever recorded was this June, July and August 2016. The last eleven months have been the hottest on record and August tied July for the warmest month ever worldwide (the average of 6,300 weather stations across the globe). August was the 11th consecutive month the monthly global temperature record was broken. Amidst this sobering climatic news is the anniversary of one of the coldest summers since weather data compilation began. The "Year Without a Summer," 1816, wasn't just chilly, it was so extreme that widespread crop failures cursed all of North America and large regions across Europe.
A half foot of snow fell throughout Upstate New York and towns in New England endured 18 inches during a bizarre snowstorm on June 6th and 7th. But it was the persistently frigid weather throughout the summer that most profoundly impacted people. The passage of two brutal cold fronts brought widespread killing frosts in early July and again in mid-August. (Remember this was long before even railroads existed, making it impossible to ship many foodstuffs from other parts of the country.) Crop failures were widespread not only in North America but much of Asia and Europe. The loss of a large portion of the rice crop in China resulted in catastrophic famine. Still recovering from the destruction and economic upheaval of the Napoleonic Wars, food riots broke out in France and the United Kingdom. A three year-long typhus epidemic began in famine-stricken Ireland, killing about 100,000.
The July 17, 1816 edition of the Brattleborough Reporter wrote that "no man living can furnish a parallel to this present season." The Vermont newspaper continued, "From every part of the United States, north of the Potomac, as well as from Canada, we have accounts of the remarkable coldness of the weather, and of vegetation retarded or destroyed by untimely frosts." Those that lived called 1816 "eighteen hundred and froze to death."
The primary cause of the disaster was the eruption of Mount Tambora in Indonesia. It blew massive amounts of volcanic material (estimated to be nearly 20 cubic miles of pyroclastic debris) into the atmosphere. Washington State's Mount Saint Helens, by contrast, produced only a quarter of a cubic mile of material during its 1980 eruption. The pre-eruption height of Tambora was over 14,000 feet; the caldera crater that was left was over 2,000 feet high. Much of that material became airborne and the finer dust and ash remained in the stratosphere for months, some for several years. This blocked sunlight and altered weather throughout the following year. The material that ended up in the stratosphere persisted, too, since it was above the altitude where rain could wash it back to the surface.
Eighteen-sixteen might seem like an interesting climatic oddity 200 years later, but we might also look at it as a cautionary tale. Sudden climatic change, no matter why it's happened, can cause disastrous environmental change with serious social and economic repercussions.
More on the long streak of record warmth can be found at NASA.
Climate and Weather
Understanding Pennsylvania Snow
The Flood of 1947
The Hottest Day
Rising Sea Level
Cold Winters & Big Pictures
Rainy Junes: 1972 & 2015
Penn State's Weather World
The Paris Accord
2016's Peculiar Snowstorm
Two Different Winters: 1936 & 2016
The Year Without A Summer
Pennsylvania's Hottest Summer