Illinois Emergency Preparedness Guide

Illinois' Multi-Hazard Reality

Illinois stretches nearly 400 miles from the Wisconsin border to the Ohio River confluence with the Mississippi. This geographic diversity creates vastly different hazard profiles across the state—northern Illinois battles brutal winters while southern Illinois faces earthquake risk from the New Madrid fault. Yet tornadoes threaten the entire state, and the Mississippi River system creates flooding potential from border to border.

The state's terrain—predominantly flat agricultural land—makes Illinois exceptionally vulnerable to tornadoes. With few natural barriers to disrupt storm systems, severe weather can race across the plains with little warning. Chicago's urban landscape creates its own hazards: urban heat islands intensify summer heat, aging infrastructure fails during stress events, and millions of people must shelter in a metropolitan area spanning multiple counties.

What makes Illinois preparedness complex is the stacking of hazards. A spring day might bring tornadoes followed by flash flooding. A winter storm might combine heavy snow, ice accumulation, and dangerous wind chills. Summer heat waves stress the power grid precisely when air conditioning demand peaks. Illinois families must prepare for the full spectrum of Midwest weather extremes.

Tornadoes: Illinois' Premier Threat

Illinois consistently ranks among America's most tornado-prone states. The flat terrain, convergence of air masses, and position in the transition zone between Tornado Alley and Dixie Alley create ideal conditions for violent rotating storms.

Illinois Tornado History

The Tri-State Tornado of 1925 remains the deadliest tornado in American history. This F5 monster traveled 219 miles across Missouri, Illinois, and Indiana, killing 695 people—including 613 in Illinois alone. Towns like Murphysboro, West Frankfort, and Gorham were devastated. This single event demonstrates that Illinois tornadoes can be catastrophically violent.

More recently, the Washington, IL tornado (November 2013) reminded Illinoisans that violent tornadoes occur outside the traditional spring season. This EF4 tornado destroyed over 1,000 homes and killed 3 people on a November morning.

The April 2024 tornado outbreak produced 28 tornadoes across Illinois in a single day, including an EF3 near the Quad Cities. Climate patterns suggest such outbreaks may become more frequent.

Tornado Patterns in Illinois

• Peak season: April-June (but can occur any month)
• Peak time: Late afternoon/evening, but nighttime tornadoes are common
• Most active region: Central Illinois corridor
• Average warning time: 13 minutes (but can be much less)

Tornado Safety for Illinois

In your home:

• Go to basement immediately (most Illinois homes have basements)
• If no basement: interior room on lowest floor (bathroom, closet, hallway)
• Stay away from windows, exterior walls, and corners
• Cover yourself with mattress, blankets, or sleeping bag
• Wear shoes and have phone nearby

In an apartment or condo:

• Go to lowest level interior hallway or bathroom
• Avoid elevators (power can fail mid-ride)
• Know your building's designated shelter area
• In high-rise: interior room below 10th floor if possible

Severe Thunderstorms: More Dangerous Than You Think

While tornadoes grab attention, severe thunderstorms cause more cumulative damage and deaths in Illinois. These storms produce:

Straight-Line Winds

Derechos—organized wind storms that can produce 100+ mph gusts across hundreds of miles—regularly affect Illinois. The August 2020 Midwest Derecho caused over $11 billion in damage, primarily in Iowa but affecting western Illinois significantly.

Even without derechos, individual storms can produce "microburst" wind gusts exceeding 100 mph. These cause tornado-like damage in concentrated areas.

Large Hail

Illinois supercells routinely produce hail larger than baseballs. Major hail events cause:

• Hundreds of millions in vehicle damage
• Widespread roof replacement needs
• Agricultural crop destruction
• Injuries to anyone caught outside

Flash Flooding

Illinois' flat terrain and heavy agricultural tile drainage can actually increase flash flood risk by concentrating runoff. Urban areas face particular danger:

• Chicago's combined sewer system can overflow during 1.5"+ rainfall
• Basement flooding affects thousands of homes annually
• Viaduct and underpass flooding traps vehicles
• The 1996 Chicago flood caused $35 million in damages

Turn Around, Don't Drown: More people die in flash floods than tornadoes in most years. Never drive through flooded roadways.

Winter Weather: Illinois' Long Cold Season

Illinois winters vary dramatically from north to south, but the entire state faces significant winter hazards.

Blizzards

Major blizzards can paralyze Illinois for days:

• Blizzard of 1967: Dumped 23 inches on Chicago, stranded thousands
• Blizzard of 1999: 21.6 inches in Chicago, $100+ million in losses
• Groundhog Day Blizzard 2011: 20+ inches with thunder, lightning, and 50+ mph gusts

Modern blizzards still shut down highways, airports, and businesses. Lake Michigan can enhance snowfall in northeast Illinois through "lake-effect" mechanisms.

Ice Storms

Ice storms cause the most prolonged outages in Illinois. Heavy ice accumulation (0.5"+ ice) brings down trees and power lines, causing:

• Power outages lasting days to weeks
• Impassable roads until temperatures rise
• Structural damage to trees and buildings
• Dangerous conditions for emergency responders

Extreme Cold

Polar vortex events can plunge Illinois temperatures to -20°F to -30°F with wind chills reaching -50°F to -60°F:

• January 2019: Chicago reached -23°F (-52°F wind chill)
• Frostbite possible in minutes on exposed skin
• Pipes freeze, furnaces struggle to keep up
• Vehicle failures common

Winter Preparation

• Heating backup: Space heaters, generator, or alternative heat source
• Pipe protection: Insulation, know main shutoff location
• Vehicle kit: Blankets, shovel, sand, jumper cables, snacks, water
• Home supplies: 3-7 days of food and water not requiring cooking
• Carbon monoxide detectors: Essential when using backup heating

Flooding: The State's Costliest Hazard

Illinois' extensive river systems create persistent flood threats. The state experienced catastrophic flooding during the Great Flood of 1993, which caused billions in damages and reshaped flood policy nationwide.

Mississippi River Flooding

The entire western border of Illinois lies along the Mississippi River. Major floods affect:

• American Bottoms: Flood-prone lowland near East St. Louis
• Quad Cities: Rock Island and Moline face regular flooding
• Quincy area: Historic flooding impacts
• Cairo: Confluence of Mississippi and Ohio rivers creates extreme flood risk

Illinois River Flooding

The Illinois River and its tributaries flood regularly, affecting Peoria, LaSalle-Peru, and numerous smaller communities. Spring snowmelt combined with heavy rain creates peak flood conditions.

Chicago Area Flooding

Despite massive flood control infrastructure (including the Deep Tunnel project), Chicago still experiences significant flooding:

• Combined sewer overflows during heavy rain
• Basement flooding in older neighborhoods
• Viaduct and underpass flooding
• Lake shore flooding during high lake levels and storms

Flood Preparation

• Know your flood zone (FEMA flood maps)
• Purchase flood insurance (standard policies don't cover floods)
• Elevate critical utilities above flood level
• Never drive through flooded roads
• Have evacuation route planned away from rivers

Extreme Heat: Chicago's Deadliest Event

The 1995 Chicago heat wave killed over 700 people in five days—more than any other weather event in recent Illinois history. This tragedy revealed the deadly potential of heat, particularly in urban environments.

Heat Wave Risk Factors

• Urban heat island: Chicago can be 10-15°F hotter than surrounding suburbs
• High-rise buildings: Upper floors become dangerously hot without AC
• Elderly isolation: Many victims in 1995 were elderly living alone
• Power grid stress: Peak demand can cause outages when cooling is most needed
• Humidity: Illinois humidity makes heat index much higher than actual temperature

Heat Safety

• Know cooling center locations in your community
• Check on elderly relatives and neighbors daily
• Never leave children or pets in vehicles
• Stay hydrated—don't wait until you're thirsty
• Know heat exhaustion vs. heat stroke symptoms
• If AC fails, go to air-conditioned location (mall, library, cooling center)

Earthquakes: Southern Illinois' Hidden Risk

While most Illinoisans don't consider earthquake preparedness, southern Illinois faces significant seismic risk from the New Madrid Seismic Zone—one of the most active earthquake zones in North America.

The New Madrid Threat

In 1811-1812, the New Madrid fault produced four magnitude 7+ earthquakes that:

• Were felt across the eastern United States
• Caused the Mississippi River to briefly flow backward
• Created Reelfoot Lake in Tennessee
• Rang church bells in Boston, 1,000+ miles away

A similar event today would devastate southern Illinois. FEMA estimates a major New Madrid earthquake could:

• Cause thousands of deaths in the region
• Create $300+ billion in direct economic losses
• Damage bridges across the Mississippi, cutting transportation links
• Produce significant damage throughout southern Illinois

Earthquake Preparation

• Secure water heaters and heavy furniture
• Know how to shut off gas
• Practice Drop, Cover, and Hold On
• Keep shoes and flashlight by bed
• Have emergency supplies that won't be blocked by fallen items

Regional Preparedness Priorities

Chicago Metro (Cook, DuPage, Lake, Will Counties)

Primary threats: Severe storms, tornadoes, extreme heat, winter storms, urban flooding

• Know your building's tornado shelter location
• Have backup plan for high-rise evacuations (fire, power failure)
• Multiple warning methods for severe weather
• 3-7 day supplies minimum (limited storage in apartments)
• Know cooling center locations for heat emergencies

Northern Illinois (Rockford, DeKalb region)

Primary threats: Tornadoes, severe storms, blizzards, flooding

• Storm shelter or safe room critical (high tornado risk area)
• Comprehensive winter supplies and vehicle kit
• River flood awareness
• Agricultural community mutual aid networks

Central Illinois (Springfield, Peoria, Champaign)

Primary threats: Tornadoes, severe storms, flooding, winter weather

• Highest tornado risk zone in state—shelter essential
• Illinois River flood awareness
• Multiple tornado warning methods
• Storm spotter network participation beneficial

Southern Illinois (Carbondale, Mt. Vernon, Cairo)

Primary threats: Tornadoes, earthquakes, flooding, severe storms

• Earthquake preparedness (New Madrid zone)
• Extended self-sufficiency supplies (rural areas)
• Ohio and Mississippi river flood awareness
• Tornado shelter access critical

Metro East (East St. Louis, Belleville)

Primary threats: Flooding, tornadoes, severe storms, earthquakes

• Flood insurance essential (American Bottoms flood zone)
• Earthquake preparedness for New Madrid zone
• Tornado shelter access
• Evacuation routes away from river

Illinois Emergency Resources

• Illinois Emergency Management Agency: iema.illinois.gov
• Illinois Road Conditions: gettingaroundillinois.com
• Chicago OEM: chicago.gov/oemc
• NWS Chicago: weather.gov/lot
• NWS Lincoln (Central IL): weather.gov/ilx
• NWS St. Louis (Southern IL): weather.gov/lsx

Illinois Emergency Kit Essentials

Year-Round Supplies

• NOAA weather radio with SAME alerts (critical for tornadoes)
• Water: 1 gallon per person per day for 3-7 days
• Non-perishable food for 3-7 days
• Flashlights with extra batteries
• First aid kit
• Prescription medications (7-day supply)
• Cash (ATMs/card readers fail without power)
• Phone chargers (battery-powered and vehicle)
• Important documents in waterproof container

Winter Additions

• Alternative heating source with proper ventilation
• Extra blankets and warm clothing
• Carbon monoxide detectors
• Ice melt and quality snow shovel
• Vehicle emergency kit

Summer Additions

• Battery-powered fans
• Electrolyte drinks
• Cooling center locations list
• Light-colored, loose-fitting clothing