How the year without a summer gave us Frankenstein

Mount Tambora erupted in April 1815, and the cold, wet year that followed in Europe became known as the year without a summer. Frankenstein began in that rain, at Villa Diodati near Geneva in June 1816 [1]. The volcano set the weather. The story itself came from a dare, a book of ghost stories and one sleepless night.

The library's card puts it in seven words: a volcano cancelled summer and invented Frankenstein. I read its source, the Wikipedia article on the year, and then Mary Shelley's own account in the introduction she wrote for the 1831 edition of the novel [2]. A rainy week can turn into "a volcano wrote a book" after enough retellings, so I wanted the two pages to agree on how far the link between the year without a summer and Frankenstein really goes.

What happened to the weather in 1816

The numbers are modest on paper. Average global temperatures fell by 0.4 to 0.7 °C, according to the article, and "Summer temperatures in Europe that year were the coldest of any on record between 1766 and 2000" [1]. A fraction of a degree across the whole planet hides much larger swings in particular places and weeks.

Britain kept the longest thermometer series. The Central England temperature record logged 1816 as the eleventh coldest year since 1659, with the third coldest summer and the coldest July on record [1]. The same article reports brown snow in Hungary, coloured by volcanic ash, and red snow in northern Italy through the year.

The harm came through food. Low temperatures and heavy rain ruined harvests in Britain and Ireland, food prices rose across Europe, and the article calls the riots of 1816 and 1817 the most violent period on the continent since the French Revolution [1]. People rioted outside bakeries "with the cause of the problems unknown", in the article's words. Nobody in 1816 blamed an island on the far side of the world.

How does a volcano in Indonesia cool Europe

Tambora sits on Sumbawa, in what is now Indonesia. Its 1815 eruption ranks 7 on the volcanic explosivity index and threw out at least 37 cubic kilometres of rock, the largest eruption in at least 1,300 years [1]. The column climbed above 43 km, into the stratosphere [3].

Height is the whole trick. The coarse ash fell out within one or two weeks, while the finest particles stayed up for months or years [3]. The eruption released sulphur dioxide, and in the summer of 1815 a "dry fog" hung over the north-eastern United States that neither wind nor rain could shift [3]. The article then names what it was: "It was later identified as a stratospheric sulfate aerosol veil." [3]

That veil spread round the globe and blocked part of the sunlight for the following year [1]. It also explains the delay. The eruption peaked in April 1815, and the cold summer that people wrote about came more than a year later, in 1816 [1]. The planet was already cool, too: the eruption fell near the end of the Little Ice Age, and a smaller eruption of Mayon in the Philippines in 1814 may have added to the effect [1].

The cost on the ground was far worse than a ruined holiday. Estimates of the dead on Sumbawa, Lombok and nearby islands vary widely, and Clive Oppenheimer put the total at no fewer than 71,000 [3].

What did Mary Shelley say about that summer

Mary Shelley's introduction is the primary source, and it is short. In the summer of 1816 she, Percy Bysshe Shelley and their party became neighbours of Lord Byron near Geneva. At first they spent their time on the lake. Then the weather turned: "But it proved a wet, ungenial summer, and incessant rain often confined us for days to the house." [2]

Indoors, a book of German ghost stories in French translation came their way. Byron proposed the contest, and Shelley records his words: "We will each write a ghost story" [2]. There were four of them. Byron began a tale and later printed the fragment at the end of his poem Mazeppa, and John Polidori tried an idea about a skull-headed lady and gave it up.

Shelley herself had nothing for days. She describes being asked each morning whether she had thought of a story, and answering no. The idea came after a night of talk between Byron and Percy Shelley about the principle of life and whether galvanism could animate a corpse. Lying awake, she saw "the pale student of unhallowed arts kneeling beside the thing he had put together" [2]. The next day she began writing.

Did the volcano really give us Frankenstein

It sounds fake because the chain is long. A mountain explodes in Indonesia, sulphur drifts round the world, the Swiss summer fails, and a young writer on holiday comes home with Frankenstein's creature. Each link sounds like a stretch on its own, and the whole thing reads like a story told backwards to make history neat.

It holds up because each link has a source, provided the claim stays modest. Tambora cooled the summer, the cold summer brought rain, and Shelley's own words put the rain at the start of the contest [2]. The novel's original preface, dated Marlow, September 1817, says the same thing plainly: "The season was cold and rainy" [2]. It also adds a detail the legend drops. "The weather, however, suddenly became serene", the friends went off into the Alps, and only her story was finished.

The fair objection comes from Alan Marshall, a lecturer at Mahidol University, who calls the link a myth. He argues the cold of 1816 is not cleanly Tambora's doing, and that the misery Shelley saw across Europe had a bigger cause: "A far more significant contributor to human misery at this time was the Napoleonic Wars" [4]. He counts 5 million dead in those wars by 1815 and lists other inputs to the novel, among them the Luddites and her own experience of childbirth [4]. On the narrow claim, that bad weather kept her indoors long enough to start writing, Shelley's account is the evidence, and she never mentions a volcano.

The claim against the source

The Dracula row comes from the Year Without a Summer article, which also credits that summer with Byron's poem "Darkness" [1].

Related facts from the library

Krakatoa, which erupted in 1883, has its own card in the library: the sound that circled the planet four times. Weather turning history is a pattern in the history pages too, as in the hot summer of stench that built London's sewers. And since Marshall's case rests on the wars, the library's note that Napoleon was a perfectly normal height is another case of a legend outrunning its source. More from the period sits under history facts.

Questions

Why is 1816 called the year without a summer?

Europe's summer of 1816 was the coldest on record between 1766 and 2000, and in Central England July was the coldest ever logged. Frosts, floods and failed harvests followed across the Northern Hemisphere, and food riots broke out in many European cities [1]. The name records how the season felt to people who lived through it, more than any single measured figure.

What caused the year without a summer?

The main cause is generally held to be the April 1815 eruption of Mount Tambora on Sumbawa, in present-day Indonesia. It put sulphur into the stratosphere, where it formed a veil that blocked part of the sunlight for more than a year. Earlier eruptions, including Mayon in 1814, and the tail end of the Little Ice Age added to the cooling [1].

Did Mary Shelley know about the volcano?

Nothing in her 1831 introduction or the 1818 preface mentions a volcano. She writes only that the summer was wet and ungenial and that rain kept the party indoors. At the time the cause of the cold and the failed harvests was not known, and the link to Tambora was made by later researchers [2].

Who else wrote a story during Byron's contest?

Byron started a tale and printed the fragment after his poem Mazeppa. John Polidori later drew on that fragment for The Vampyre, an early vampire story that came before Dracula. Percy Shelley began a story from his own early life and dropped it. Only Mary Shelley finished, and her story grew into the novel.