Due to multiple factors, expect to potentially pay more when booking in September. For low rates, August can be a great choice for travel to Osaka Kansai Intl Airport. Flights to Osaka Kansai Intl Airport from Cleveland in August are about $1,008 on average during August, but can be found for as low as $600.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Cleveland to Osaka Kansai Intl Airport as you normally would.