Hurricanes are among the most powerful weather systems on Earth. They are large rotating tropical cyclones that can produce destructive winds, torrential rainfall, storm surge, coastal flooding, inland flooding and, in some cases, tornadoes.
The same type of tropical cyclone is called a hurricane in the Atlantic and eastern North Pacific, a typhoon in the western North Pacific, and a cyclone in other parts of the world. The hazards are broadly similar even though the name differs by region.
A hurricane can remain dangerous far beyond the coastline. Heavy rainfall can cause flooding hundreds of kilometres inland, while strong winds, falling trees, damaged buildings and power outages can create additional hazards.
Understanding how hurricanes form, their warning signs, major dangers and appropriate safety measures can help communities prepare before a storm arrives.
WHAT IS A HURRICANE?
A hurricane is an organised tropical cyclone with a closed circulation and sustained winds of at least 74 mph (119 km/h).
Hurricanes generally develop over tropical or subtropical oceans. They are powered by heat and moisture from warm ocean water. As warm, moist air rises and water vapour condenses, heat is released into the atmosphere, helping the storm develop and intensify.
A mature hurricane can contain:
- A central eye
- An eyewall surrounding the eye
- Large spiral rainbands
- Powerful thunderstorms
- Very strong winds
- Extremely heavy rainfall
The apparent calm of the eye can be misleading. Dangerous conditions can return rapidly when the opposite side of the eyewall passes over an area.
HOW DO HURRICANES FORM?
Hurricanes require a combination of atmospheric and oceanic conditions.
1. WARM OCEAN WATER
Warm ocean water provides the primary energy source.
NOAA explains that tropical cyclones generally require ocean temperatures of around 26.5°C or warmer through a sufficient depth, allowing large amounts of water to evaporate and provide heat and moisture to the developing storm.
2. MOIST AIR
Warm, humid air rises from the ocean surface.
As the air rises, water vapour condenses into clouds and thunderstorms. The condensation releases heat, providing additional energy to the developing tropical cyclone.
3. A PRE-EXISTING WEATHER DISTURBANCE
Many hurricanes begin as a tropical wave or another area of disturbed weather containing thunderstorms.
If environmental conditions are favourable, the disturbance can become increasingly organised and develop into a tropical depression, tropical storm and eventually a hurricane.
4. SUFFICIENT ROTATION
The Earth's rotation helps give tropical cyclones their characteristic circulation.
This is why tropical cyclones generally develop away from the equator rather than directly on it.
5. LOW WIND SHEAR
Strong differences in wind speed or direction with height can disrupt a developing tropical cyclone.
Relatively low vertical wind shear allows the storm's thunderstorms and circulation to remain organised and can support further development.
THE MAIN DANGERS OF HURRICANES
A hurricane is dangerous not simply because of its wind speed. Several different hazards can occur at the same time.
The National Hurricane Center identifies storm surge, heavy rainfall and inland flooding, high winds, rip currents and tornadoes among the major hazards associated with tropical cyclones.
1. EXTREME WINDS
Powerful hurricane winds can damage or destroy structures and infrastructure.
They can:
- Remove roofs
- Break windows
- Damage walls
- Knock down trees
- Destroy signs
- Damage vehicles
- Bring down electrical poles
- Turn loose objects into dangerous projectiles
Flying debris can cause serious injuries even when a person is inside a building.
This is why people should stay indoors and away from windows when hurricane-force conditions occur.
2. STORM SURGE
Storm surge is an abnormal rise in sea level caused primarily by a storm's winds pushing seawater toward the coast.
It is one of the most dangerous hurricane hazards for coastal communities.
Storm surge can:
- Flood coastal communities
- Destroy buildings
- Damage roads and bridges
- Erode beaches and dunes
- Carry debris inland
- Contaminate freshwater supplies
- Threaten lives through drowning
The National Hurricane Center notes that storm surge and large waves can cause severe destruction along coastlines and that storm surge can travel several miles inland.
3. HEAVY RAINFALL AND FLOODING
Hurricanes can produce enormous amounts of rain.
Flooding can occur:
- Along rivers
- In cities
- In low-lying areas
- In coastal communities
- In mountainous areas
- Far inland from the coast
Flash flooding may develop quickly, while river flooding can continue for days after the storm has weakened.
For people living inland, flooding can be one of the most serious hurricane-related threats.
4. RIP CURRENTS AND DANGEROUS WAVES
Even when a hurricane does not make direct landfall, its large waves and powerful ocean currents can create dangerous conditions along distant coastlines.
People may be at risk at beaches, particularly swimmers and surfers.
During hurricane-related coastal conditions, people should stay out of the water and follow beach and emergency warnings.
5. TORNADOES
Some hurricanes and tropical storms can produce tornadoes, particularly in their outer rainbands.
This means communities can experience another dangerous weather phenomenon in addition to the hurricane's wind and rain.
6. LANDSLIDES AND MUDSLIDES
Heavy rainfall from a hurricane can saturate soil and destabilise slopes.
This can trigger:
- Landslides
- Mudslides
- Rockfalls
- Debris flows
The risk can be especially serious in mountainous or hilly areas.
7. POWER OUTAGES
Strong winds, falling trees and flooding can damage electrical infrastructure.
Power outages can affect:
- Homes
- Hospitals
- Businesses
- Communication systems
- Water supplies
- Transportation
Power may remain unavailable for an extended period after a major storm.
8. CONTAMINATED FLOODWATER
Floodwater may contain:
- Sewage
- Bacteria and other germs
- Chemicals
- Human and animal waste
- Debris
- Dangerous objects
- Fallen electrical wires
CDC advises people to stay out of floodwater and avoid driving through flooded areas.
WARNING SIGNS OF AN APPROACHING HURRICANE
Hurricanes are generally monitored well in advance using satellites, weather observations, computer models and other forecasting systems.
Important warning signs include:
- An approaching tropical cyclone identified by meteorological authorities
- Official hurricane or tropical cyclone watches
- Official hurricane or tropical cyclone warnings
- Increasing winds
- Increasing rainfall
- Rising coastal water levels
- Dangerous waves and surf
- Flood warnings
- Evacuation orders
People should not rely only on what they can see outside. A hurricane can remain dangerous even when conditions temporarily appear calm.
HURRICANE WATCH VS HURRICANE WARNING
Understanding the difference between a watch and a warning is extremely important.
HURRICANE WATCH
A hurricane watch means hurricane conditions are possible within the specified area.
According to CDC guidance, a hurricane watch is generally issued when hurricane-force winds are possible, giving people time to prepare.
What should you do?
- Monitor official weather information.
- Prepare your emergency supplies.
- Secure loose objects.
- Check evacuation routes.
- Charge essential devices.
- Prepare medicines and important documents.
- Be ready to evacuate.
HURRICANE WARNING
A hurricane warning means hurricane-force conditions are expected in the specified area.
This is the time to complete preparations and follow official instructions immediately.
If authorities order an evacuation, leave as instructed.
Do not wait until roads are flooded or winds become extremely strong.
HOW TO STAY SAFE BEFORE A HURRICANE
Preparation should begin well before the storm arrives.
1. CREATE A FAMILY EMERGENCY PLAN
Discuss:
- Where your family will go
- Where the nearest emergency shelter is
- Which evacuation routes to use
- How family members will contact one another
- Where to meet if separated
- How to help children, older adults and people with disabilities
- What to do with pets
CDC recommends knowing evacuation routes and nearby shelters before a hurricane occurs.
2. PREPARE AN EMERGENCY KIT
A basic emergency kit should contain:
- Drinking water
- Non-perishable food
- Prescription medicines
- First-aid supplies
- Flashlights
- Extra batteries
- Power banks
- Mobile phones and chargers
- Important documents
- Cash
- Hygiene supplies
- Basic tools
- Essential supplies for babies and children
- Pet supplies where necessary
A hurricane can interrupt electricity, water supplies and transportation, so households should be prepared to remain self-sufficient for a period of time.
3. SECURE YOUR HOME
Before strong winds arrive:
- Bring outdoor furniture indoors.
- Secure loose objects.
- Bring bicycles and gardening equipment inside.
- Secure construction materials.
- Protect windows using appropriate shutters or other approved measures.
- Clear gutters and drainage areas.
- Check the roof for obvious problems.
- Move important belongings away from areas vulnerable to water intrusion.
CDC recommends securing loose outdoor items and protecting windows and doors before a hurricane.
4. PROTECT IMPORTANT DOCUMENTS
Keep important documents in waterproof protection.
Examples include:
- Identification documents
- Passports
- Insurance documents
- Property documents
- Medical information
- Financial records
Digital copies stored securely can also be useful if original documents are lost or damaged.
5. PREPARE FOR POWER LOSS
Charge:
- Mobile phones
- Power banks
- Rechargeable lights
- Emergency communication devices
Have flashlights and spare batteries available.
Avoid relying exclusively on electricity-dependent equipment.
WHAT TO DO DURING A HURRICANE
1. STAY INDOORS
If authorities tell you to shelter at home, remain indoors.
Stay away from:
- Windows
- Glass doors
- Skylights
- Exterior doors
- Areas exposed to flying debris
CDC recommends staying in a room without windows or another protected interior location when sheltering from a hurricane.
2. DO NOT GO OUTSIDE DURING THE EYE
One particularly dangerous situation occurs when the hurricane's eye passes overhead.
The weather may suddenly become calm, and people may mistakenly believe the storm has ended.
However, extremely dangerous winds can return when the opposite side of the eyewall arrives.
Never leave your shelter simply because the weather temporarily becomes calm.
Wait for an official announcement that the danger has passed.
3. FOLLOW EVACUATION ORDERS
If authorities issue an evacuation order:
Leave immediately according to the recommended route.
Do not remain at home simply to protect property.
CDC specifically advises people never to ignore an evacuation order.
4. NEVER DRIVE THROUGH FLOODWATER
Flooded roads can hide:
- Deep holes
- Washed-out roads
- Debris
- Strong currents
- Damaged bridges
- Electrical hazards
Vehicles can stall or be swept away by moving water.
CDC advises people never to drive through flooded areas.
5. STAY AWAY FROM POWER LINES
Never touch fallen electrical cables.
Stay well away from damaged electrical infrastructure and report it to the appropriate authorities or electricity provider.
6. MONITOR OFFICIAL INFORMATION
During the storm, continue monitoring official emergency information through available channels.
Do not rely solely on social media rumours or unverified messages.
HOW TO REDUCE HURRICANE DAMAGE
Hurricanes themselves cannot be prevented, but communities can reduce their vulnerability.
1. IMPROVE BUILDING RESILIENCE
Buildings in hurricane-prone areas can be designed or strengthened to better withstand:
- High winds
- Heavy rainfall
- Flooding
- Wind-borne debris
Building standards, proper roof construction and appropriate window protection can reduce damage.
2. IMPROVE DRAINAGE
Good drainage can help reduce the effects of intense rainfall.
Communities can reduce flood risk through:
- Proper stormwater drainage
- Regular maintenance of drains
- Flood-control infrastructure
- Protection of natural drainage systems
- Appropriate land-use planning
3. PROTECT COASTAL AREAS
Coastal vegetation, dunes, wetlands and other natural features can provide some protection against waves and storm-related flooding.
However, they should not be treated as a substitute for evacuation or engineered flood protection when authorities issue warnings.
4. AVOID HIGH-RISK DEVELOPMENT
Urban and coastal planning should take into account:
- Flood-prone areas
- Storm-surge zones
- Coastal erosion
- River floodplains
- Landslide-prone slopes
Proper planning can reduce the number of people and structures exposed to hurricane hazards.
WHAT TO DO AFTER A HURRICANE
The end of strong winds does not necessarily mean the area is safe.
1. WAIT FOR OFFICIAL CLEARANCE
Do not immediately return to evacuated areas or damaged buildings.
CDC advises people to stay away from damaged buildings until authorities determine that they are safe.
2. AVOID FLOODWATER
Floodwater may contain dangerous contaminants, chemicals, sewage, animals and electrical hazards.
Avoid walking or driving through it whenever possible.
3. WATCH FOR FALLEN POWER LINES
Treat every fallen electrical cable as potentially dangerous.
Never touch it or attempt to move it yourself.
4. BE CAREFUL WITH DAMAGED BUILDINGS
Buildings may have:
- Structural damage
- Broken glass
- Damaged electrical systems
- Gas leaks
- Unstable walls
- Flood damage
Leave immediately if you hear unusual shifting, cracking or other sounds that could indicate structural failure.
SAFE CLEANUP AFTER A HURRICANE
Cleanup can produce additional injuries.
When cleaning:
- Wear appropriate protective clothing.
- Use gloves and suitable footwear.
- Avoid contaminated water.
- Be careful around broken glass and debris.
- Do not enter severely damaged buildings until they are declared safe.
- Keep children away from damaged areas.
- Follow official instructions concerning water and food safety.
CDC also warns that floodwater can contain germs, chemicals, waste, animals and other contaminants.
GENERATOR SAFETY
Power outages after hurricanes can lead people to use portable generators.
Generators should never be operated indoors, inside garages, or near doors and windows, because they can produce deadly carbon monoxide.
Use generators only outdoors and sufficiently away from buildings according to the manufacturer's safety instructions.
HURRICANE SAFETY FOR CHILDREN
Children should be taught simple rules:
- Stay indoors when instructed.
- Stay away from windows.
- Never play in floodwater.
- Never approach fallen electrical cables.
- Never go outside during the temporary calm of the eye.
- Follow parents, teachers and emergency authorities.
- Do not touch unknown debris or damaged equipment.
Parents should prepare emergency supplies specifically for children, including food, medication, clothing and comfort items.
WHAT NOT TO DO DURING A HURRICANE
❌ Do not ignore evacuation orders.
❌ Do not drive through floodwater.
❌ Do not go outside during the storm because conditions temporarily appear calm.
❌ Do not stand near windows during strong winds.
❌ Do not approach the coastline during dangerous conditions.
❌ Do not touch fallen electrical cables.
❌ Do not enter damaged buildings without clearance.
❌ Do not use generators indoors.
❌ Do not drink potentially contaminated water.
❌ Do not allow children to play in floodwater.
❌ Do not assume the danger has ended immediately after the storm passes.
HURRICANE SAFETY CHECKLIST
BEFORE THE HURRICANE
✔ Monitor official weather warnings.
✔ Prepare an emergency kit.
✔ Prepare drinking water and food.
✔ Secure outdoor objects.
✔ Protect windows where appropriate.
✔ Charge phones and power banks.
✔ Prepare important documents.
✔ Know evacuation routes.
✔ Identify emergency shelters.
✔ Make a family communication plan.
DURING THE HURRICANE
✔ Stay indoors.
✔ Stay away from windows.
✔ Follow official instructions.
✔ Evacuate immediately if ordered.
✔ Never drive through floodwater.
✔ Stay away from the coast and dangerous waterways.
✔ Do not go outside during the eye of the storm.
AFTER THE HURRICANE
✔ Wait for official clearance.
✔ Avoid floodwater.
✔ Stay away from fallen power lines.
✔ Avoid damaged buildings.
✔ Use generators safely outdoors.
✔ Check drinking-water safety.
✔ Clean up carefully.
✔ Watch for additional flooding, landslides and structural hazards.
CONCLUSION
Hurricanes are complex and dangerous weather systems that can affect communities through extreme winds, storm surge, heavy rainfall, flooding, dangerous waves, rip currents, tornadoes and landslides. A hurricane does not have to make direct landfall in a particular neighbourhood for that area to experience dangerous conditions.
The best way to reduce the risk is preparation and early action.
Know the hazards in your area, monitor official warnings, prepare an emergency kit, secure your home and understand your evacuation route. If authorities order an evacuation, leave promptly. If you are instructed to shelter, stay indoors and away from windows.
Most importantly, never underestimate floodwater, storm surge or hurricane winds.
KEY SAFETY MESSAGE
PREPARE EARLY, FOLLOW OFFICIAL WARNINGS, EVACUATE WHEN ORDERED AND STAY IN A SAFE SHELTER UNTIL AUTHORITIES CONFIRM THAT THE DANGER HAS PASSED.
Sources: NOAA National Hurricane Center, NOAA Ocean Service, CDC and other U.S. government hurricane-safety guidance.
