 Omak experiences four distinct seasons . Summers are hot and relatively dry , with a daily average of 72 @.@ 2 ° F ( 22 @.@ 3 ° C ) in July , while winter is the wettest season of the year , with 22 @.@ 3 inches ( 570 mm ) of snowfall between November and February . Spring and autumn are mild seasons with little precipitation . The city is located in plant hardiness zone 6a , according to the United States Department of Agriculture ( USDA ) . In July 2012 , a severe thunderstorm occurred in Omak , producing heavy rainfall , gusty winds and hail , and forced the temporary closure of U.S. Route 97 and requiring repairs to public streets . Omak was affected by the 1872 North Cascades earthquake — the state 's largest historical earthquake — which occurred on December 14 , 1872 . The epicenter was at Omak Lake . The earthquake had a magnitude of between 6 @.@ 5 and 7 @.@ 0 and was followed by an aftershock . Another earthquake with minor shaking affected the city in November 2011 . 
