The internal temperature of a medium rare steak should be between 130°F and 135°F. Here are the internal temperatures for other levels of doneness:

• Rare: 120°F to 125°F
• Medium: 140°F to 145°F
• Medium well: 150°F to 155°F
• Well done: over 160°F

Its important to note that the temperature of the steak will continue to rise a few degrees after its removed from the heat source, so its best to remove the steak from the heat when its about 5 degrees below the desired temperature. Additionally, its recommended to let the steak rest for a few minutes before serving to allow the juices to redistribute and the temperature to even out.