Hawaii Safety & Hazards Guide

The Centipede packs a powerful bite

Wildlife, Plants, Insects, & Arthropods

Relevant to All Islands

For the most part, you are very safe on the Hawaiian Islands from all animal and plant life. There are no large predators or snakes, and there are few plants that will irritate when hiking (no poison oak or ivy, for example). However, other hazards still exist.

The main culprit we've encountered in the animal world is an arthropod, the centipede. In Hawaii, these aggressive arthropods carry quite a punch, and getting bitten or stung by one is not what you want during your visit to the islands. The resorts usually spray for them very well, but be careful with any shoes left outside at\ night, etc.

Another arthropod that gets a lot of attention is the cane spider, but it's mostly hype. The brown cane spider is mostly feared due to its appearance/size. It is about the size of a can of tuna, including its long legs. Typically, it will run versus defend itself, and the bite of a cane spider is rarely dangerous. Nonetheless, it is worth mentioning.

Scorpions are also on the drier sides of the islands, but they usually stay out of sight. Mosquitoes typically frequent the wetter sides of the islands, so prepare accordingly. Geckos are nothing to be worried about; they're the cute lizards that keep the bug population somewhat under control. On the Big Island, the coqui tree frog is the other adorable- albeit pesky- resident. Especially prevalent on the Hilo/Puna side of the island, they will likely be music to your ears the first night. By the fifth night, you'll probably be plugging your ears! The coqui frogs are an invasive species threatening the balance of vulnerable native ecosystems. 

The many edible plants and fruits of Hawaii also create a hazard. Many visitors believe they can pop just about anything in Hawaii in their mouths for a little taste... not so! Many plants here are poisonous, and no fruits or plants should be eaten unless you know it is safe. Remember that many plants have similar-looking fruits.

Beware of the high UV index in Hawaii

The Sun

Relevant to All Islands

The sun - A UV index of nearly 14+ daily speaks for itself. We recommend at least 15+ sun block in Hawaii at all times. Also, please use reef-safe sunscreen to help preserve Hawaii's delicate marine environment. Please don't ruin your visit by trying to get that tropical tan; the tan will be gone within a month of your return home; the sun damage and memory of the burns will last much longer.

Use caution around fresh water bodies of water in Hawaii

Streams, Rivers, & Pools

Relevant to All Islands

Our primary message here is short and sweet: Pay attention to the stream's flow where you are and be aware of the weather inland. Streams and rivers can quickly change flow rates and heights in the islands. Flash flooding is a regular occurrence in some places. One good rain, even far inland from where you are, can substantially cause a stream to rise. If you're crossing any streams or rock hopping, pay close attention to the weather and the water levels. Anytime you are crossing a stream or river where it empties into the ocean, we advise crossing inland a bit. Dangerous rip currents can form in the sea at the mouth of a river or stream. Hiking poles may be handy for any crossings you make, as they provide extra limbs to help you keep your balance.

If you go swimming, make sure you don't swallow any water, and try to cover up any open wounds you may have so that water can't get in them. In Hawaii, leptospirosis can be found in water contaminated by animal droppings, and you do not want to get mixed up with this disease. It causes flu-like symptoms and, in rare cases, death.

Beware of safety hazards in the ocean & on the beach

Ocean Life & The Beach

Relevant to All Islands

If you've ever been to the beach, you likely already know about the hazards of the ocean. Rip currents, sharp coral, large waves, surf, and various creatures are just a few. The most notable sea creatures to watch out for on the Big Island are coral, jellyfish (Portuguese Man-of-War), and sea urchins. If you plan to swim, snorkel, or SCUBA dive on the island, do your homework and become fully educated on the hazards of the ocean here.

Vog over lava flows on the Big Island

Volcano Area Hazards

Relevant to the Big Island and portions of Maui

The first thought that comes to mind when you hear about Hawaii's volcano danger is probably the lava hazards. In reality, the 2,000°F lava may pose the least risk to the sensible person. Hawaii Volcanoes National Park and the surrounding Volcano area of the Big Island are subject to several hazards that are easy to overlook or aren't something you'd expect without prior knowledge of the site. While this mainly applies to the Big Island, Maui is no exception as it has many areas covered with recent (geologically speaking) lava flows, especially in South Maui. Let's go over a few of these hazards.

Hiking on Lava:

Around the Big Island and especially at the end of Chain of Craters Road, you can hike over lava. As we mention on our Hawaii Geology page, there are two types of lava: pahoehoe and a'a flow. Grossly simplified, pahoehoe is smooth, and a'a is sharp, brittle, and crumbly. Trying to walk over a'a is a fool's errand. The only traversable lava flows are hardened pahoehoe flows like those found at the end of Chain of Craters Road.

Currently, Chain of Craters is the only location you can also safely approach active flows (when they are present). The dangers involved in crossing lava, even pahoehoe lava, are primarily due to the razor-like sharpness of the hardened lava. Even the pahoehoe flows are as sharp as glass, and you can easily cut yourself- especially your hands- in a fall. Extreme care and precautions should be taken when hiking over lava. Long pants and gloves are always a good idea. The heat produced by the sun hitting the black asphalt-like lava surface deters many visitors from wearing long pants, but don't risk injury. The pahoehoe surface is smooth but can contain all sorts of variations in the surface that can catch your foot or cause you to stumble. It would be best to remain keenly aware of the texture of the flows you are walking across, as shallow lava tubes can cave in, dropping you a few inches (or more) below the surface. If you plan to make any lengthy hikes, take adequate water, as dehydration can occur quickly on the shadeless black lava surface.

Viewing Active Lava Flows:

As a continuation of the above hazard and warning, we again encourage all visitors to be prepared for hiking they do on hardened flows to see active flows. When approaching an active flow, your body will only let you get so close before the heat forces you to stand back, but use common sense and don't attempt to get any closer than you must to view the lava safely. Lava temperatures average around 2,000°F. Do not try to cross any active flow upslope, as active flows are often concealed in lava tubes beneath the surface, and you do not want to find one by mistake.

Do not cross any National Park boundary ropes in the park, as they are in place for your protection. The park service is relatively liberal about how close they will allow people to get to lava flows, so traversing beyond the boundaries they've set up is extremely dangerous. Usually, the roped-off areas are near the lava entry point into the ocean. Explosions, deadly steam plumes, and gasses make this a dangerous place to be near. Furthermore, all lava benches are roped off for the same reason. Lava benches can easily collapse at any time, spelling inevitable catastrophe for anyone on the bench. Just two days before writing this article, a 45-acre bench had collapsed in a single night; yes, 45 ACRES!  

Volcanic Gasses & Vog:

Where hot lava meets the sea, and especially at the source of the eruption, the volcano produces a deadly concoction of gasses. It's estimated that Kilauea puts out about 2,500 tons of sulfur dioxide daily. Enough of those fumes can kill someone almost instantly (as if you needed another reason to stay behind those barriers the park service puts up). Even far away from the sources of these sulfur dioxide plumes, visitors can experience another type of gas- vog.

Vog is a mixture of sulfur dioxide gas, water vapor, carbon dioxide, dust, and other airborne particles. Vog can exist in reasonably high amounts around the volcano area and even wrap around the island into Kailua-Kona, depending on trade wind activity. Hilo, Puna, Kohala, and the Hamakua coast are usually vog free.

Vog can affect different people in different ways. Visitors with asthma and respiratory troubles will have the most problems. In our experiences with vog, we've been mostly unaffected by it. It's unpleasant to smell, but it has never had any adverse effects on us. We have, though, on a few occasions, had unusually heavy vog settle upon us near the end of Chain of Craters Road- usually coming from Pu'u O'o up the pali/cliff- when the trade winds were blowing light. Often, this causes coughing and a burning sensation in the eyes, nose, and mouth. If possible, avoid areas where you notice a lot of vog. Generally, you can see it in the air like a low cloud moving south down the coastline from the volcano. If you are caught in thick vog, try to get out of it as quickly as possible. You can call 808-885-7143 for a vog index update.

If you want more information on vog, hiking over lava, and viewing lava, please consult the park rangers inside Hawaii Volcanoes National Park.

Please respect private property while visiting Hawaii.

General Sightseeing

Many locations in Hawaii are private property, and visitors should try to avoid trespassing on such properties. If a trail says it's closed, it's closed. If you see a sign that says kapu, then it's off-limits. Do not explore places you're unsure about - waterfalls, pools, trails, caves, lava tubes, etc. You likely wouldn't want people exploring your backyard at home, so be mindful of and respectful to residents here. Your courtesy will be much appreciated.

Nene Geese in Hawaii

Hazards YOU Pose

It may or may not surprise you, but we humans are one of Hawaii's most significant risks. If you refer to the History of Hawaii page, you'll learn about Hawaii's endemic species- species found ONLY in Hawaii. Thus, as visitors to these islands, we must remember that we pose one of the most significant hazards to the rare and endangered species that live here and only here. There are a few general guidelines to follow while on the islands.

1.) As a general rule, it is best to avoid all wildlife. You should know feeding or touching wild animals in Hawaii is illegal. That means no feeding the geese (Nene), touching the turtles (Honu), or swimming with the dolphins. These three issues are something we hear about and witness a lot in Hawaii. It seems innocent enough, but consider the consequences of your casual interaction with these creatures. Nene no longer fear our cars and are being killed off at an alarming rate. The touch of a human can deliver deadly infections to the honu as it basks in the sun or swims in a shallow pool. As a reminder, people must stay at least 10 feet from sea turtles on land and in the ocean, 50 feet away from Hawaiian monk seals, 50 yards away from dolphins, and 100 yards away from humpback whales.

2.) Kapu means kapu (off-limits). The government has made many areas ecologically or culturally fragile kapu (off-limits). Sensitive places include lava tubes, caves, burial grounds, heiaus (temples), etc. Please show hoihi (respect) for the laws that protect these beautiful and fragile places.

3.) Remember that trails and roads exist for a reason. It's easy to get off the beaten path and do a bit of exploring, but keep in mind that "just off that beaten path" in Hawaii could be the home to a variety of animals and plants you might not be aware of.

4.) Don't take the lava rocks or sand home with you; selling black sand in Hawaii is illegal. You'll surely hear the legend of Pele cursing all those who take her "children" away from the islands. If that won't stop you, local airport screeners will likely confiscate any they find in your luggage.