Fire Danger Index
Chandler Burning Index (CBI)
The Chandler Burning Index (CBI) uses the air temperature and relative humidity to calculate a numerical index of fire danger. That number is then equated to the Fire Danger severity of either extreme, very high, high, moderate, or low. It's based solely on weather conditions, with no adjustment for fuel moisture.
CBI < 50
|
Low |
50 < CBI < 75
|
Moderate |
75 < CBI < 90
|
High |
90 < CBI < 97,5
|
Very high |
CBI > 98
|
Extreme |
|
85
Tucson
|
Current risk
All fine dead fuels ignite readily and fires start easily from most causes. Unattended brush and campfires are likely to escape. Fires spread rapidly and short-distance spotting is common. High-intensity burning may develop on slopes or in concentrations of fine fuels. Fires may become serious and their control difficult unless they are attacked successfully while small.
|
Formula --> CBI = (((110 - 1.373 * RH) - 0.54 * (10.20 - T)) * (124 * 10
(-0.0142 * RH)))/60
T = Air temperature |
[°C]
|
/ |
RH = Relative humidity |
[ %]
|
Application --> CBI = (((110 - 1.373 *
23.1 ) - 0.54 * (10.20 -
26.4444)) * (124 * 10
(-0.0142 * 23.1 )))/60 ≅
85