Due to multiple factors, expect to potentially pay more when booking in August. For low rates, February can be a great choice for travel to Dallas. Flights to Dallas from Meridian, Mississippi in February are about $296 on average during February, but can be found for as low as $201.
Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Meridian, Mississippi to Dallas as you normally would.