How Hot Is Fire?

hot-fire Credit: Richard Riley/CC-BY 2.0

Wood fires usually burn at a temperature of around 1,950 degrees Celsius. The exact temperature of the flame is dependent on external conditions such as the type of fuel being burned, available ventilation and the form of oxygen available for combustion.

The hottest flame ever produced artificially burned at a recorded 4,990 degrees Celsius. It was accomplished with dicyanoacetelyne as a fuel and an ozone atmosphere. Flames as cool as 120 degrees Celsius have been produced using precisely regulated fuel-air mixtures. This "cool fire" is only 20 degrees hotter than the boiling point of water, so the reaction has trouble maintaining combustion temperature and tends to go out quickly.