Medium Rare: Grill 8 minutes per side or to 140°F internal temperature. Medium: Grill 10 minutes per side or to 155°F internal temperature. 3. Check Doneness - Internal Temperature. Remove steaks from the grill when a quick-response meat thermometer inserted through the side of the steak to its center reads the desired temperature below. To retain juices and reach final temperature, let steaks sit for 2 minutes before cutting.