According to the Crockpot website, slow cookers reach the simmer point and stabilize on both "High" and "Low" at about 209°F. However, a Reddit post cites Crock-Pot as saying that both "High" and "Low" stabilize at the same temperature, and it is just a matter of how long it takes to reach the simmer point. Once food reaches the simmer point, total cook time is dependent on the cut and weight of meat to reach the point of maximum flavor and texture potential.

A quick guide to slow cooker settings on Millennial Homeowner states that the high temperature of a Crockpot is 300 degrees Fahrenheit, and typically recipes with the high setting on a crockpot will cook for 4 hours.

Therefore, the temperature of a crockpot on high is around 300°F.