Caves are warmer even in snow covered areas!

Caves can stay much warmer than the outside air during extreme winter cold. Deep underground, temperatures change far more slowly than they do at the surface. In many caves, the air temperature stays close to the area’s average annual ground temperature rather than following short-term weather. So if outside air falls to around −20°C (−4°F), a cave in the right climate may still remain near 0°C to +5°C (32°F to 41°F). The exact temperature depends on location, cave depth, airflow, elevation, and local geology. That stability is why caves can feel surprisingly warm in winter, and cool in summer.