What degree should a rib roast 3 pounds be internally to be rare?

For a 3-pound rib roast to be considered rare, the internal temperature should reach about 125°F (52°C). It's important to use a meat thermometer to ensure accuracy. Remember that the roast will continue to cook slightly after being removed from the oven, so you may want to take it out a few degrees before it reaches the target temperature. Allowing it to rest for at least 15-20 minutes will help redistribute the juices and enhance the flavor.