Tropospheric temperatures tended to cool after the Agung (8°S) eruption in 1963, but warm after the El Chichón (17°N) eruption in 1982. Thus, over the one-year period following the eruptions, Northern Hemisphere surface temperature is indicated as cooling 0.34°C after Agung, but warming 0.37°C after El Chichón, a difference significant at the 0.5% level according to Student';s t-test. This difference in Northern Hemisphere temperature change is mainly due to differences in north temperate latitudes where, over the one-year period, the surface temperature is indicated as cooling 0.36°C after Agung but warming 1.27°C after El Chichón. It is proposed that the warming after El Chichón is mostly due to the anomalously warm sea surface temperature (SST) in the eastern equatorial Pacific (El Niño) in 1982–83, the relation between SST and tropospheric temperature being an obvious one in the tropics but of a more indirect nature in midlatitudes. The best evidence so far for a tropospheric cooling due to El Chichón is in the north subtropics (10–30°N) where the zonally-averaged air temperature continued to cool after the eruption in the spring of 1982, whereas SST in the region 0–10°S, 180–80°W warmed abruptly, the opposite of the relation usually observed. Since this SST returned nearly to normal at the end of 1983, the cooling effect of El Chichón should be more evident in 1984.