The Mount St. Helens Volcanic Eruption of 18 May 1980: Minimal Climatic Effect

An energy-balance numerical climate model was used to simulate the effects of the Mount St. Helens volcanic eruption of 18 May 1980. The resulting surface temperature depression is a maximum of 0.1 degrees C in the winter in the polar region, but is an order of magnitude smaller than the observed natural variability from other effects and will therefore be undetectable.