Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Cork to Houston as you normally would.
For a flight from Cork to Houston, you will be flying from Cork. Cork (ORK) is just 4.0 mi from the center of the city. Cork is the only Cork airport and it handles 0 outbound flights to Houston per day. 0 airlines have flights to Houston from Cork on a regular basis.