Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Kahului to Rome Fiumicino Airport as you normally would.
Due to multiple factors, expect to potentially pay more when booking in July. For low rates, December can be a great choice for travel to Rome Fiumicino Airport. Flights to Rome Fiumicino Airport from Kahului in December are about $1,234 on average during December, but can be found for as low as $528.