Source: N5PA Website

Chandler Burning Index Calculation

The Chandler Burning Index (CBI) is a fire danger severity value that is calculated from the air temperature and the relative humidity. This numerical value is then indexed to relative severity adjectives. The input values for this calculation are taken from the local the Temperature and Relative Humidity you key in (there is no adjustment for fuel moisture) and these can and do change throughout the day. The current CBI presented here differs from that of the National Weather Service which computes a 30-day Chandler Burning Index based on forecasted weather conditions for the month.