Very hot!! Here are some temperatures recorded at different times and locations:
- The eruption temperature of Kīlauea lava is about 1,170 degrees Celsius (2,140 degrees Fahrenheit).
- The temperature of the lava in the tubes is about 1,250 degrees Celsius (2,200 degrees Fahrenheit).
- The tube system of episode 53 (Pu'u O'o eruption) carried lava for 10 kilometers (6 miles) from the vent to the sea. The tubes contained the heat so efficiently that the lava was still a sizzling 1,140 degrees Celsius (2,085 degrees Fahrenheit) when it reached the ocean.
- The color of incandescent rock gives a crude estimate of temperature. Yellow indicates a temperature of about 1,000–1,200 degrees Celsius (1,832–2,192 degrees Fahrenheit). Orange indicates a slightly cooler temperature of about 800–1,000 degrees Celsius (1,472–1,832 degrees Fahrenheit). Red is even cooler, about 600–800 degrees Celsius (1,112–1,472 degrees Fahrenheit).
- The outer surface of erupting lava cools incredibly quickly (by hundreds of degrees per second) when it is first exposed to air.