A wild fire is an undesirable fire occurring in the natural environment. Fuel is any living or dead material that will burn. Fuels such as dead plants, dry leaves, pine needles and grass are burn more readily than moist green plants because the dead material contains less moisture. Heat is usually supplied by a lightning strike to a tree or dry grass. People also can provide heat by carelessly starting a fire or leaving a fire unattended.
Weather is one of the most significant factors in determining the severity of wild land fires.
The intensity of fires and the rate with which they spread is directly rated to the wind speed, temperature and relative humidity. Climatic conditions such as long term drought also play a major role in the number and intensity of wildfires. Accurate and timely weather information is vital to the planning and execution of strategies for suppressing wildfires. An accurate weather forecast can mean life or death to a fire fighter and is also critical in protecting forest and range lands as well as the increasing number of homes in the wild land urban interface. The objective of the National Weather Service Fire Weather Program is to provide meteorological support to wild land fire management agencies for the protection of life and property.