The San-yo is the sunniest region in Japan, and almost anytime is a good time to visit. The northern shore, or San-in, gets a stronger dose of winter than the southern one, but it has a wonderfully long spring. Like most of Japan, Western Honshu gets dreadfully muggy by midsummer, but the wind off the Nihon-kai cools the San-in coast. Summer festivals and autumn colors are spectacular throughout the region, and attract many tourists, so reserve well ahead if you are traveling then.