The Fire Danger Index, issued by the National Weather Service, serves as a guide to reduce the number of uncontrollable outdoor fires. Fire Danger Indexes provide an indication of wildland fire potential and overall fire activity to a given area. The Fire Danger Index provides citizens with needed information about fire safety conditions. The index contains five ratings – low, medium, high, very high, and extreme. Fires are more likely to occur on higher index days, and more likely to grow in size. The Fire Danger Index does not predict how a specific fire will behave; however, the indices do give an indication of overall fire activity.
Normally, the NWS calculates the Fire Danger Index for each county using predicted values for temperature, humidity, wind speed, cloud cover and vegetative greenness. The NWS also issues fire weather forecasts and red flag warnings that refer to weather conditions, which could sustain extensive wildland fire activity. These forecasts and warnings are used to alert land management agencies and land users when dangerous burning conditions and increased potential for wildland fires exist. When the vegetative greenness component deteriorates to the point of creating an unusual fuel condition with a high energy release component, the North Dakota Fire Council will scientifically analyze this condition and recommend specific counties be placed in the extreme category, regardless of daily weather conditions regarding temperature, humidity, wind speed and cloud cover. The following chart lists index ratings and fire danger descriptions:
|Index Rating||Fire Danger Description|
|LOW||Weather and fuel indicators show the probability of fire occurrence is low.|
|MEDIUM||Weather and fuel conditions indicate some potential for fire occurrence. Expect predictable fire behavior with moderate rates of spread.|
|HIGH||Fires are active. Expect moderate and occasional high rates of spread.|
|VERY HIGH||Fires spread rapidly and show erratic behavior. Dangerous burning conditions exist.|
|EXTREME||Potential for large fires exist. Fires spread rapidly. Extreme fire behavior is probable. Critical burning conditions exist.|