Are volcanic eruptions affecting the amount of rain and snow?
Are volcanic eruptions that are ongoing around the world affecting the amount of rain and snow that has been occurring over the past several months here in the United States?
— Halina Gumiela
No, not recently. Volcanoes throw a great deal of debris into the atmosphere, but much of it (such as heavy particles like pumice and ash) falls out either in the vicinity of the volcano or downwind within a few days. However, gases (like sulfur dioxide) mix into the atmosphere and are carried away. In sufficient quantity, these gases can have planetary cooling effects that persist for a few years. The most recent volcano to do this was Mount Pinatubo (in the Philippine Islands) in a June 1991 eruption. It threw so much sulfur dioxide into the atmosphere that global temperatures dropped 0.9 degrees in the following three years.