These Natural Disasters Can Occur in Hawaii! Are You Prepared?

Natural disasters that occur in Hawaii

Hawaii was the 50th US state to join the Union on August 21, 1959.

It’s generally recognized for its 8 main islands, however, it’s actually comprised of a chain of 137 islands, of which only seven are inhabited— the eighth, Niihau, is strictly preserved and inhabited by the Robinson family, the descendants of the Sinclairs who bought the island from King Kamehameha V in 1864.

The state of Hawaii is a tropical paradise, where surfing, boogie boarding, and hula dancing were invented. Its rich cultural history, unmatched scenic views, iconic sunrises and sunsets, rainbows, and relaxed lifestyle make it a top destination for tourists and travelers alike.

Each of the islands in the Aloha State enjoys a diverse climate, including generally mild temperatures, sunny skies, as well as the possibility of light misty rain on one side of the island while it’s raining heavily just a few miles away.

The Aloha State was geographically formed out of volcanic eruptions and is the only state that is entirely surrounded by water, thereby making it prone to several natural hazards.

What natural disasters does Hawaii have?

Hawaii’s most common natural disasters include wildfires, floods, landslides, volcanoes, earthquakes, tsunamis, and power outages. Hurricanes and severe storms may also occur but they’re rare.

Between 1953 and 2019, Hawaii declared 51 major disasters, of which fires and floods happened the most according to the Federal Emergency Management Agency (FEMA).

1. Wildfires

One of Hawaii’s most threatening disasters is wildfires. When calculating the percentage of total land area burned per year, Hawaii ranks among the highest in the United States with an estimated 0.5%. 

Wildfire season is slowly turning into a year-round possibility, but July and August remain the worst months because of the dry vegetation and strong winds. The extended fire season may also be linked to the growth of non-native plant species which burn at higher intensities.

The worst wildfire in the Aloha State’s history occurred in 1969. It affected the Northwestern part of Hawaii and burned over 47,000 acres. Fast-forward a few decades, 2018 saw another terrible fire season.

According to the Hawaii Wildfire Management Organization, 98% of the state’s wildfires are human-caused. It’s important for civilians to do their part in becoming part of the solution, rather than the problem.

A flame or small bonfire should never be left unattended, especially during periods of high winds. Always keep plenty of water on hand to prevent a fire from growing out of hand.

Other safety practices for wildfires include creating defensible space around your property so that there’s plenty of space between your home and any trees, shrubs, and overhanging branches. It's also important to have an evacuation plan.

The distance traveled by wildfires can be alarming if the conditions are just right. Therefore, you shouldn’t rely on your property’s landscaping as the only way to prevent a fire from reaching your home.

No matter what disaster you may be facing, you and your family’s well-being is the priority. Learn how to prepare for a wildfire here and be sure to practice your evacuation plan.

2. Floods

Like most tropical places, it rains frequently in Hawaii — in fact, it is home to America’s rainiest city: Hilo.

On average, the Aloha State receives 70 inches of rain annually, making it especially prone to floods and flash floods.

April 2018 brought thunderstorms with record rainfall to Kauai and Oahu. In as little as 48 hours, up to 32 inches of rain fell over some cities— that's almost 3 feet of water! Thousands of residents were evacuated— some were rescued by helicopter, bus, and boat.

The overall result of these heavy rains included the destruction of approximately 530 homes, erosion of roads, mountainsides, and bridges, and the sweeping away of power lines, debris, crops, trees, and animals. The total damages reached $125 million (2018 USD), but luckily no deaths were reported.

Flooding across the Hawaiian islands is also a result of storm surge and high surf. A study shows that many popular tourist beaches, like Waikiki Beach in the county of Honolulu, will experience consistent flooding in the next 15 to 20 years due to the sea level rise.

Floods and flash flooding can be devastating. In order to prepare for a flood, you should determine your property’s level of risk.

Since the topography of the world is constantly changing, new flood-prone areas may develop over time. It would be a great idea to have your home inspected and re-evaluated every 10 or 15 years to ensure there are no vulnerabilities present.

If you’re in a flood zone, you should determine ways to raise or strengthen your home to prevent future damage.

Hawaii homeowners should know that most homeowners insurance policies don't cover flood damage. Consider looking into the National Flood Insurance Program to see which options are available to you.

When you're under the threat of heavy rain, find a safe place to immediately. Get to higher ground and do not attempt to cross flood waters.  

Learn flood mitigation and prevention tips here!

3. Landslides

Landslides can occur anywhere where there are mountains or slopes. With a combination of 1,137 mountains across all of the Hawaiian islands, you can expect there to be no exceptions when it comes to landslides in the Aloha State.

Hawaii’s history shows that catastrophic landslides have occurred throughout the islands.

According to the Monterey Bay Aquarium Research Institute, “The Nu’uanu and Wailau landslides tore the volcanoes forming eastern Oahu and northern Molokai, respectively, in half, and deposited blocks large enough to have been given names as seamounts. Tsunamis generated during these slides would have been devastating around the entire Pacific Basin.”

This historic landslide is the reason why the north side of Molokai is so steep.

The United States Geological Survey has made maps for each of the islands highlighting the landslide vulnerability of each.

  • The Big Island of Hawai has an overall low landslide susceptibility, with moderate susceptibility along the northern coast (specifically around Mauna Kea which is the Big Island's highest point) and other scattered places throughout the island.

  • Maui, Moloka’i, and Lanai have a moderate susceptibility with a high to very high susceptibility in select places.

  • Kaho’olawe has a low overall susceptibility with a moderate susceptibility along parts of its coast.

  • The Island of Kauai has an overall moderate susceptibility with select portions of high to very high susceptibility.

  • Ni’ihau has an overall low susceptibility, with a mountainous region of moderate susceptibility.

  • O’ahu has an overall moderate susceptibility with select regions ranging from high to very high susceptibility. The well-known Nu’uanu submarine landslide, located along the northeastern coast of O’ahu, measures 235 km wide and 35 km long and is among the largest in the world. 

Large-scale landslides can't be prevented but small ones can be mitigated. If your home is located near slopes or hills, you may want to implement strategies to protect your property from possible future damage. In this guide, we highlight some ideas for you to consider.

If you live in a town or city with a high risk of landslides, learn the warning signs and have a rapid evacuation plan, including the knowledge of alternative roads.

4. Volcanoes

The Hawaiian Islands were formed as a result of volcanic activity. At present, there are four active and two dormant volcanoes that are being monitored by the U.S. Geological Survey Hawaiian Volcano Observatory. The Big Island contains four of them.

A volcano classified as “active” means that it has erupted in recent history. A dormant volcano means that it hasn’t erupted in a very long time, but scientists speculate that it may erupt again in the future.

Hawaii is home to the largest volcano in the world: Mauna Loa. Its last eruption occurred in 1984.

The youngest volcano on the Aloha State is Kīlauea. You may remember that a short time ago, Kilauea volcano’s eruption was making major news headlines. While it’s still erupting today, it began erupting back in 1983 and its most active period was between 2008 and 2018.

Some of the main volcanic hazards affecting Hawaii are lava flows, explosive eruptions, particle clouds, ash and gas emissions, volcanic debris, and vog.

Vog, otherwise known as volcanic smog, occurs when gasses and particles [primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide gas (SO2)] emitted from the erupting volcano react with sunlight, moisture, and oxygen. Vog is something many Hawaiians are familiar with, especially those who live southwest of Kīlauea. 

It’s important to know a volcano’s warning signs so you can prepare accordingly. Many times, the circumstances make it safer for families to shelter at home until the volcano is done spewing ash and particle clouds.

Other times, as was the case with the eruption of Kīlauea, lava flow covered entire communities. The people living in those homes had no choice but to evacuate.

Depending on the volcano’s inner makeup and how it erupts, you will have to have an evacuation and/or shelter-in-place plan. Practice both scenarios and prepare enough food, water, and emergency supplies to sustain you and your family members for a minimum of two weeks.

To learn more about volcano preparedness, check out this guide.

5. Earthquakes

Due to its geographical location, earthquakes are very common in Hawaii. In fact, thousands of them happen each year, meaning that you can expect several small earthquakes to occur every day!

Contrary to the cause of earthquakes in most other places, seismic hazards in the Aloha State are the result of volcanic eruptive processes and the movement of magma. There are no fault lines in Hawaii.

The Big Island of Hawaii experiences the most large earthquakes out of all the other islands because it's the region with the most active volcanoes, specifically the southern district where Kīlauea, Mauna Loa, and Lō‘ihi are located.

The majority of quakes average a magnitude of 3.9 or less, with a 4.0 to 4.9 happening roughly once a month, a 5.0 to 5.9 happening once every 1.5 years, a 6.0 to 6.9 happening once every 7.7 years, and anything over a 7 magnitude earthquake happening once every 55.8 years.

Before the ground starts shaking, you should have an emergency plan for yourself and your family. Create a safe environment in your home, by securing large items (like your TV, refrigerator, and anything that can break).

Practice taking cover for safety, especially with your kids. Finally, know what to look for when inspecting your home for damages. Check out this complete earthquake guide for mitigation and safety tips! Finally, be sure to expect and prepare for tsunamis, which may occur after earthquakes.

6. Tsunamis

Hawaii is made up of islands, so it’s clear that coastal hazards are a likely natural threat. Since historical records began registering natural disasters (roughly around 1813 to 1814), there have been at least 85 tsunamis in the Aloha State.

Fifteen of the eighty-five caused significant damage, and eighty-one of them originated outside of the islands— mostly from South America and the Pacific Northwest.

The worst tsunami in Hawaiian history occurred on April 1, 1946. It was triggered by an underwater earthquake near the Aleutian Islands off the coast of Alaska. It killed 159 people. This remains Hawaii's deadliest natural disaster to date.

The original reading of the earthquake was said to have a magnitude of 7.1, however, seismologists have studied the effects of the tsunami and believe that a more accurate calculation would be that it had a magnitude of 8.2.

Regardless of the mysterious intensity that resulted from this tsunami, Hawaii experienced massive devastation. The tsunami waves reached the state within five hours and reached average heights of two to three-story buildings with a maximum height of 45 feet (in Haena).

It caused significant property damage to over 1,400 beach-front properties, including the entire waterfront in Hilo. The tsunami injured 163 people and killed 173. The reported cost of damages was $25 million (1946 USD).

Hawaii is surrounded by the threat of tsunamis. Since the coastal areas extend far and wide, it’s important to pay attention to the posted tsunami evacuation signs near the beaches.

In the event of a tsunami warning, get to higher ground immediately. Tsunami waves can reach unbelievable heights and are likely to cause coastal surges and flooding.

If you live in a coastal area or are spending a day at the beach, pay attention to evacuations signs within the tsunami evacuation zone. Tsunami waves travel at high speed and can wipe out the coastal region in minutes.

For the complete guide on tsunami safety, click here.

7. Power Outages

Electricity is vulnerable to all types of natural disasters, so becoming prepared for a long-term outage is highly recommended since it’s a key part of your emergency plan.

One of the longest outages in Hawaiian history occurred on December 26, 2008, during a rare and powerful thunderstorm. It is believed that lightning struck power lines and caused the electric system to trip.

Almost the entire island of Oahu was left in complete darkness for up to 12 hours. Some may remember this event because President Obama was in Oahu at the time vacationing with his family.

Outages can happen anytime and anywhere, so being prepared to adjust to a lack of power, even if momentarily, is beneficial. One of the best ways to know that you'll have everything you need at the time you need it is by testing the equipment you already have.

If you have an emergency kit at home, inspect all the contents to make sure they're up to date. If you don't have a kit, get one.

Then, select a day on your calendar to have a "family blackout day". For at least 24 consecutive hours, you should turn off your electricity's main and use the items in your kit, plus whatever else you have on hand at home, to prepare your meals, charge your mobile devices, etc.

Doing this will help you determine where your emergency plan needs to be improved and reevaluate the efficiency of the items in your kit. For more tips on power outage preparedness, check out this guide.

8. Tropical Storms and Hurricanes

While tropical storms can occur any time of year, Hawaii’s hurricane season begins on June 1st and lasts through November 30th. Its most active months are July and August.

Only two hurricanes have ever made landfall in Hawaii’s recorded history.

Hurricane Dot made landfall in August 1959 as a category 1 storm and caused minor damage to Oahu and the Big Island, including downed trees, power lines, coastal surges, and flooding.

The second and worst hurricane to make landfall in Hawaii was Hurricane Iniki (Category 4) which made landfall in September 1992. It caused extensive damage of over $1.8 billion and caused 6 deaths.

Even though hurricanes are rare, their remnants (whether it be in the form of a tropical storm, tropical cyclones, or tropical depressions) are usually enough to make an impact.

There have been many close calls when it comes to hurricanes approaching the Hawaiian Islands, such as:

  • Hurricane Iwa in November 1982 (Category 1)
  • Hurricane John in August/ September 1994 (Category 5)
  • Hurricane Douglas in July 2020 (Category 4)
  • Hurricane Barbara in July 2019 (Category 4)
  • Hurricane Hector in August 2018 (Category 3)

Many of these storms caused significant damages to the islands.

Hurricanes are a huge threat to coastal areas. Hawaii, being surrounded by the Pacific Ocean, cannot escape this threat. It would be wise to install storm shutters or have plywood (measured to fit around your windows) ready to go if a hurricane is forecasted. 

Stay tuned to the local weather forecast for any updates on developing coastal storms. Be prepared to travel inland if you have to evacuate and have plenty of food, water, and emergency supplies to cover the needs of you and your family members. Check out this guide for a complete list of mitigation and safety tips.

9. Severe Storms

Hawaii has a stable semi-tropical climate in which the weather averages 70 to 80 degrees year-round. October through April are the wettest months, however, some places experience precipitation daily.

Because of its temperate climate, severe thunderstorms, lightning, tornadoes, and hail sometimes occur, but on very rare occasions.

If on one of those rare occasions, a thunderstorm approaches while you’re playing sports, having a picnic, or out and about enjoying nature, find a safe place to take shelter.

Lightning can strike outside of the boundaries of the storm cloud, so be sure you don't stay outside or hang out indoors near exterior windows. Resume outdoor activities 30 minutes after the storm has passed.

For more information on staying safe during severe thunderstorms, visit our guide here.

Natural disaster resources for Hawaii

In Hawaii, there are many resources to help you mitigate and overcome the natural disasters you're at risk of. These are a few for you to consider.

  • For the latest weather alerts and warnings, download the National Weather Service app on your smartphone or tablet.

    The National Oceanic and Atmospheric Administration -NOAA Weather Radio will send you real-time notifications so make sure your devices stay charged and that you’re able to hear alerts if they come through during the night.

    Another place to get updates is via your local radio and TV stations, as well as their social media pages.

  • If you’re looking for more information on preparing for a specific disaster, you can find the no-fluff detailed guides right here. Be sure to print the safety checklists at the end and keep them for future reference.

  • One of the best ways to learn preparedness skills is alongside like-minded people. The Community Emergency Response Team is a perfect place to start. CERT provides free training, simulations, and supplies to the community. Find your local CERT here!

  • Emergency situations cause high demand on certain items and resources. The Hawaii VOAD (Voluntary Organizations Active in Disasters) works with local governments, officials, and businesses. They bring together resources to the affected area during times of need. If you would like to help with recovery efforts, sign up with them online.

    Another disaster relief organization is the American Red Cross. They provide evacuation shelter, food, and supplies after an emergency declaration is made.

  • For more information on state resources with respect to the preparedness and recovery phases of disasters, visit the Hawaii Emergency Management Agency website.

I hope you enjoyed learning about the disasters that affect Hawaii.

We created an in-depth resource with guides, templates, and checklists that will allow you to customize your emergency plan according to your specific needs. Click here to get started!

Want to look up another state? Find out which disasters are likely to happen in other parts of the United States here!

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