 Lake Superior moderates the climate of those parts of Minnesota's Arrowhead Region near the shore. The lake acts as a heat sink, keeping the state's North Shore area relatively cooler in the summer and warmer in the winter. While this effect is marked near the lake, it does not reach very far inland. For example, Grand Marais on the lakeshore has an average July high temperature of 70°F (21°C), while Virginia, at about the same latitude but inland about 100 miles (161 km) to the west, has an average July high of 77°F (25°C). Virginia's average high temperature in January is 15°F (− 9°C), while Grand Marais' is 23°F (− 5°C). Just a few miles inland from Lake Superior are the Sawtooth Mountains, which almost completely confine the marine air masses and associated precipitation to lower elevations near the lake.
