Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from London, Ontario to Ohio as you normally would.
For a flight from London to Ohio, you will be flying from London. London (YXU) is just 8.6 km from the centre of the city.
Great question - YXU to CLE just means London Airport to Cleveland Hopkins Intl Airport. Now you’ll know what these unique codes when you look for flights! Cincinnati Cinci./N. Kentucky Airport (CVG), Columbus Airport (CMH), Dayton Airport (DAY), Akron/Canton Airport (CAK), Toledo Express Airport (TOL) are other airports near this flight route and their unique identifiers/IATA codes.