Initial Spread Index

Mouse over map to magnify
Class Ignition Potential Interpretation
Low Fires will be self-extinguishing.
Medium Fire can be easily suppressed with hand tools.
High Most fire can be successfully controlled using power pumps and hose.
Extreme Some fires will be difficult to control.
  • The ISI is a measure of the head fire indicator and rate of fire spread. The higher ISI index indicates higher difficulty of control in grassland. It is a combination of the effects of the wind speed and Fine Fuel Moisture Code.

  • Image courtesy of the Malaysian Meteorological Department.