Figure 3.8. Mean annual temperature and mean summer temperature (June, July, August) for Durham, NH, 1886-1995. The years of high sulfur-producing volcanic eruptions in the 20th century are noted. All of these eruptions are known to have had an impact on northern hemisphere climate, although the very strong El Niño of 1982-1983 offset the cooling of the El Chichón eruption. The latitude and season of the eruption determines when the greatest cooling occurs in New England.