Due to multiple factors, expect to potentially pay more when booking in June. For low rates, May can be a great choice for travel to Santa Ana. Flights to Santa Ana from Fort McMurray in May are about C$ 755 on average during May, but can be found for as low as C$ 566.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Fort McMurray to Santa Ana as you normally would.