National Fire Danger Rating System
You can find a summary of the background of NFRDS here.
This is the simple what it means summary:
Numeric Class / Adjective Class
1 / LOW
Fires will not spread beyond heat of campfire or brush fire.
2 / MODERATE
Fires will start from open flame, camp or brush fire. Spreads slowly.
3 / HIGH
Fires will start from a lighted match and spread rapidly in dry grass, slower with moisture. Will continue to spread until extinguished.
4 / VERY HIGH
Fires will start readily from match or glowing embers and spreads rapidly as it increases in size. May crown young conifers.
5 / EXTREME
Fires start readily from sparks or cigarette butts. Spread and crown rapidly. Spot fires common. All burn fiercely and may blow up unless controlled promptly.
Categories: .Fire Danger and Weather Forecasts
