There are earthquake "seasons", at least in the Himalayas
EARTHQUAKE SEASON IN THE HIMALAYAN FRONT (TOP STORIES)
Scientists have long searched for what triggers earthquakes, even
suggesting that tides or weather play a role. Recent research
spearheaded by Jean-Philippe Avouac, professor of geology and
director of the Tectonics Observatory at Caltech, shows that in the
Himalayan mountains, at least, there is indeed an earthquake season.
It's winter.
Details: http://mr.caltech.edu/media/Press_Releases/PR13081.html