Each year, about 3,000 wildfires burn 30,000 acres or more of forest and grassland. Missouri's wildfire season is in the spring and fall, unlike the Western states that have a summer fire season. Dead vegetation, combined with the low humidities and high winds typical of these seasons, makes wildfire risk greater at these times.
Fire danger is based upon the burning index (BI). The burning index takes into account the fuel moisture, relative humidity, wind speed, temperature and recent precipitation. The burning index is the basis for fire suppression crew staffing levels.
The Department of Conservation relies upon the news media to help warn citizens of high fire danger. A set of standardized fire danger adjectives have been developed for fire warnings. These adjectives include a brief description of burning conditions, open burning suggestions for homeowners and fire crew staffing levels. Residents should always check with their local fire department or local Department of Conservation office for local burning conditions.
Low Fire Danger
Burning index <20.
Open burning is usually safe with proper containers and precautions under low fire danger conditions. However, residents should always check on local ordinances that prohibit open burning under any conditions. Escaped fires are easy to extinguish. No fire crew staffing is planned for low fire danger conditions.
Moderate Fire Danger
Burning index = 21-30.
Open burning is usually safe with the proper precautions under moderate fire danger conditions. Burning should be done in the early morning and late evening to avoid windier conditions at midday. Escaped fires can be contained with proper fire-fighting equipment. Partial fire crew staffing is planned for moderate fire danger.
High Fire Danger
Burning index = 31-45.
Any open burning is discouraged during high fire danger. Windy conditions, low humidity and dry fuels contribute to high fire danger. Fires escape control easily and containment is difficult, endangering human safety and property. Partial or full fire staffing is planned, depending on local burning conditions.
Extreme Fire Danger
Burning index >45.
Open burning should not be attempted during extreme fire danger. Local authorities may impose burning bans. High winds and extended dry periods lead to extreme burning conditions. Open fires can quickly escape and are very difficult to control. Spot fires occur ahead of the main fire, and erratic burning conditions make fires difficult to control even for experienced fire fighters. Full fire crew staffing in planned for extreme burning conditions.
