Lava

The speed at which lava moves across the ground depends on several factors, including:

(1) Type of lava erupted and its viscosity

(2) The steepness of the ground over which it travels

(3) Whether the lava flows as a broad sheet, through a confined channel, or down a lava tube

(4) Rate of lava production at the vent.

Typically, lava flows less than 1/2 mile per hour on gentle slopes. Under specific circumstances though, lava has been previously calculated to flow at velocitiesof 18.6 miles per hour.

Lava ranges from 1,100 degrees Fahrenheit to 2000+ degrees Fahrenheit according to usgs.gov. (That's hot enough to burn or melt almost anything in its path!)