In the 4th Century B.C., Aristotle proposed that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory lead to a belief in earthquake weather, that because a large amount of air was trapped underground, the weather would be hot and calm before an earthquake. A later theory stated that earthquakes occurred in calm, cloudy conditions, and were usually preceded by strong winds, fireballs, and meteors.
However, there is no connection between weather and earthquakes. They are the result of geologic processes within the earth and can happen in any weather and at any time during the year. Earthquakes originate miles underground. Wind, precipitation, temperature, and barometric pressure changes affect only the surface and shallow subsurface of the Earth. Earthquakes are focused at depths well out of the reach of weather, and the forces that cause earthquakes are much larger than the weather forces. Earthquakes occur in all types of weather, in all climate zones, in all seasons of the year, and at any time of day.
Sometimes, we are asked: 'Do earthquakes change the weather in any way? Earthquakes themselves do not cause weather to change. Earthquakes, however, are a part of global tectonics, a process that often changes the elevation of the land and its morphology. Tectonics can cause inland areas to become coastal or vice versa. Changes significant to alter the climate occur over millions of years, however, and after many earthquakes.
USGS Web Site