While the Year Without a Summer, in 1816, occurred during the Dalton Minimum, the prime reason for that year's cool temperatures was the highly explosive 1815 eruption of Mount Tambora in Indonesia, which was one of the two largest eruptions in the past 2000 years. One must also consider that the rise in volcanism may have been triggered by lower levels of solar output as there is a weak but statistically significant link between decreased solar output and an increase in volcanism.