The Oregon coast is mild year-round but rarely warm. July, August, and September are the driest months, with daytime highs in the high teens to low twenties Celsius — pleasant but rarely sunbathing weather. These are also the busiest months; book lodging well ahead.
Winter (November to March) is wet, dramatic, and storm-watched: huge waves crash against Yaquina Head and the jetties, and gray whales pass close to shore on their migration. December and March are peak whale months and the towns put on dedicated whale-watch weeks with volunteer spotters at the headlands. Bring waterproof everything.