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How Hot Is Lava?
Basalt lava flow.
Credit: United States Geological Survey

Ice melts at 32 degrees Fahrenheit. Chocolate melts at 90 F. But rock? Now we're talking a lot more heat.

Lava, the melted rock that shoots out of volcanoes, can flow at temperatures of thousands of degrees Fahrenheit.

Lava that's on the cooler side comes out of volcanoes at only pizza oven-like temperatures of 570 F, according to the United States Geological Survey (USGS).

In the middle range of lava temperatures, the dark red lava often seen slowly crawling across parts of Hawaii , measures around 895 F. Mount St. Helens ejected material of a similar temperature, although this material flew from the mountain at 100 mph, according to USGS.

However, once a volcano gets going, the mercury really starts to climb. Bright red lava flows in Hawaii can get as hot as 1,165 F, with the glowing orange flows getting hotter than 1,600 F, according to USGS.

And when rock is seriously melting, such as the magma within the Hawaiian volcano of Kilauea , it can reach 2,120 F, according to USGS.