1816, "The Year Without a Summer"

Starting on 10-4-1815, a series of explosions of the Tambora vulcano triggered a 'Volcanic Winter' all over the world, ultimately causing the worst famines of the 19th century both in Europe and the USA. It also caused spectacularly coloured sunsets throughout the world, and global temperatures dropped by as much as 0.3°C in 1816.

The Tambora is one of Indonesia’s 130 active volcanoes, still standing at a gigantic 2800 m. on the northern Sumbawa Island. Prior to the enormous 1815 eruption it had shown no signs of volcanic activity for a thousand years.

On 10-4-1815, however, the first of a series of eruptions sent ash 20 miles into the atmosphere, covering the island with ash to a height of 1.5 meters. Five days late, the Tambora erupted violently once again, expelling so much ash that the sun was not seen for several days. The series of explosions continued for 4 months. 

Red-hot stones rained down after the grumbling volcano finally blew, and nearby settlements were completely engulfed in lava. Debris, particles and sulphur components were blown into the higher layers of the atmosphere. All vegetation on the island was destroyed by the noxious ash, and the resulting poisoned rain. Floating islands of pumice 3 miles long were observed before the coast, and even 4 years later these islands still hindered navigation. In all, so much rock and ash was thrown out of the Tambora that the height of the volcano was reduced by 1400 m. An astounding 70,000 people may have died in Indonesia as a result of burning, starvation, or poisonous gasses. 

At the time Europe was still suffering from the aftermath of the Napoleonic wars that ended in 1815. After years of desperation and destruction people hoped for better times, but the 1815 eruption released sulphur into the stratosphere, causing a global climate anomaly. 
In the spring and summer of 1816, a persistent dry 'fog' was observed in the northeastern United States and Europe, that reddened and dimmed the sunlight. The summer was rainy and cold. The states of New York and Maine experienced snow and frost in June. On the fields the crops either did not mature, or rotted away. Famine and diseases were the consequences, especially in Great-Britain, Ireland and France. 

The year 1816 has come to be known as "the year without a summer". 

Further reading: 

• Top 10 Deadly Volcano Eruptions
• Tambora Explosion Triggers 'Volcanic Winter'
• History.com: Volcanic eruption kills 80,000

Nederlandstalige versie: 1816, "Het Jaar Zonder Zomer"