Chart 4: Burn Index Categories

 
Category Weather Event Recommendation
1
Low level temperature inversion and stagnant air the entire day. No burning
2
Inversion until early afternoon and very light transport wind Mid afternoon burning only.

Inversion burn-off temperature will be given.

3
Inversion until late morning. Light transport wind.  Daytime burning only, but not until 
4
Little or no inversion. Moderate transport wind. Burning anytime.
5
No inversions. Strong gusty transport wind.  Burning with caution. Good smoke dispersion but adverse fire behavior.