For August travel, the best time to buy flights from John Glenn Columbus International Airport (CMH) to Vienna International Airport (VIE) is typically 6–12 weeks prior to departure. For lower fares, consider mid-week departures (Tuesday–Thursday) and avoid peak weekend travel. If you want fewer crowds in Vienna, schedule early-week arrivals or late August dates when some tourist peaks subside. Early morning transatlantic departures can help maximize your first day in Vienna.