Lava is typically 700 to 1,200 degrees Celsius, or about 1,300 to 2,200 degrees Fahrenheit. The hottest is fluid basaltic lava, the runny kind that pours out of Hawaiian-style volcanoes. That's blisteringly hot, but for scale, Earth's core sits around 5,200 degrees Celsius, which makes even the fiercest lava look almost mild.

Why lava glows

That orange-to-yellow glow isn't a chemical reaction or fire sitting on top of the rock. It's blackbody radiation, the light any object gives off simply because it's hot enough.

Heat something past roughly 500 degrees Celsius and it starts to glow a dull red. Push it hotter and the color shifts toward orange, then yellow, and eventually white. Lava's color is basically a thermometer you can read with your own eyes.

This is the same reason a stove burner glows red or a piece of metal turns orange in a forge. The hotter it gets, the bluer and brighter the light, all the way up to the white-hot end of the scale.

Hot, but not hot enough to melt everything

Movies love showing lava instantly vaporizing anything it touches. In reality, plenty of materials shrug it off, because their melting points sit well above lava's temperature.

Steel melts around 1,400 degrees Celsius and tungsten near 3,400. So a lava flow that tops out at 1,200 won't melt either one on contact, even though it would absolutely cook anything alive in seconds.

Not all lava is equally hot

Basaltic lava is the hottest and the runniest. Low in silica, it flows like thick syrup and reaches the top end of the temperature range, which is why those flows can travel for miles.

Lava richer in silica is cooler and far stickier. It barely flows at all, which is part of why those volcanoes tend to erupt explosively, building pressure instead of simply oozing out.

Lava's color is a free temperature gauge. The brighter and more yellow it glows, the hotter it is.

Putting the numbers in perspective

A home oven maxes out around 260 degrees Celsius. A blazing wood fire might hit 1,000. Lava sits right in that range, which is why it can set a forest alight without being anything close to the hottest thing in nature.

The Sun's surface runs near 5,500 degrees Celsius, roughly the same neighborhood as Earth's core. Lava is just the planet's interior heat leaking out, a cooled-down hint of the furnace churning thousands of miles below your feet.

So when you ask how hot lava is, the honest answer is: hot enough to be deadly, hot enough to glow, but a long way from the most extreme heat the universe has on offer.

What lava actually does to things it touches

Because lava is dense and moves slowly, it tends to push objects around or set them alight rather than swallowing them whole the way films suggest. A person couldn't sink into it like quicksand; the stuff is roughly three times denser than water.

Heat transfer also takes time. A flow can roll up to a concrete wall and char it black without instantly vaporizing it, because the rock has to dump its heat into the wall second by second.

What lava is genuinely great at is burning, scorching, and burying. Anything flammable nearby ignites from the radiant heat alone, often before the lava even arrives, which is why the danger zone around a flow extends well past where the molten rock actually reaches.

There's also the gas to worry about. A flow releases clouds of sulfur dioxide and other fumes that can be more immediately dangerous than the heat, especially when lava meets the sea and throws up a haze of steam and hydrochloric acid. The temperature, in other words, is only half the threat.

Try It Yourself

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Keep reading: how hot the Earth's core is and how volcanoes build islands. Both go deeper on the same rabbit hole.

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