Year Without a Summer cause 1815 eruption of Mount Tambora
1808, the 1808 mystery eruption (VEI 6) in the southwestern Pacific Ocean
1812, La Soufrière on Saint Vincent in the Caribbean
1812, Awu in the Sangihe Islands, Dutch East Indies
1813, Suwanosejima in the Ryukyu Islands, Japan
1814, Mayon in the PhilippinesThese eruptions had built up a substantial amount of atmospheric dust. As is common after a massive volcanic eruption, temperatures fell worldwide because less sunlight passed through the stratosphere.According to a 2012 analysis by Berkeley Earth Surface Temperature, the 1815 Tambora eruption caused a temporary drop in the Earth's average land temperature of about 1 °C. Smaller temperature drops were recorded from the 1812–1814 eruptions.The Earth had already been in a centuries-long period of global cooling that started in the 14th century. Known today as the Little Ice Age, it had already caused considerable agricultural distress in Europe. The Little Ice Age's existing cooling was exacerbated by the eruption of Tambora, which occurred near the end of the Little Ice Age.This period also occurred during the Dalton Minimum (a period of relatively low solar activity), specifically Solar Cycle 6, which ran from December 1810 to May 1823. May 1816 in particular had the lowest sunspot number (0.1) to date since record keeping on solar activity began. The lack of solar irradiance during this period would have been exacerbated by atmospheric opacity from volcanic dust.