It’s generally more expensive to depart on a Tuesday, if you have to leave on this day you can still search on Cheapflights to find great options that meet your needs.
Due to multiple factors, expect to potentially pay more when booking in April. For low rates, August can be a great choice for travel to Austin. Flights to Austin from San Antonio in August are about $627 on average during August, but can be found for as low as $57.
When flying from San Antonio to Austin, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.