If you've already worked your way through the Hawaii day-hike checklist, this is the list for what comes next. We ranked the state's hardest trails using a composite of difficulty tag (hard or expert), distance, and elevation gain, drawing from the 756 mapped Hawaii trails in our database. These ten routes are reserved for hikers with the gear, the navigation skills, and the honesty about their own limits to tackle them safely.
Hawai'i's six hikeable islands range from sea-level beach walks to the 13,800-ft alpine deserts of Mauna Kea and Haleakalā. Volcanic geology, rainforests, and knife-edge ridgelines define the experience. The Kalalau Trail (Kaua'i Nā Pali Coast), Mauna Loa summit, and Haleakalā crater traverse are Hawai'i's benchmark expert hikes. Flash floods in narrow valleys (especially Kaua'i and the Big Island), unstable volcanic rock, and exposed cliff-edge trails account for most rescues.
Our rankings here are data-driven — pulled from the 756 mapped entries OutsideAtlas tracks in Hawaii — but the data has limits worth being honest about. A composite score weights expert and hard difficulty tags alongside total mileage and elevation gain. The result favors long, vertically aggressive routes with documented technical sections — there are surely tougher off-trail objectives in the state, but those are outside the scope of a trail directory.
The Ranking
Ranked from #1 to #10. Click through any entry for the full trail page — map, elevation profile, weather forecast, and direct OpenStreetMap source link.
#1. Captain Cook Monument Trail
Captain Cook Monument Trail sits near Ocean View in Hawaii County and is rated hard — our pick for the toughest trail on the list. Expect gravel surface on a genuinely demanding grade. Local trail-association reports tend to agree this is one of the better-maintained options in the area, which matters more on a hike of this length than on a quick walk. A gravel-and-dirt tread holds up well after rain, though loose surface on descents calls for trekking poles or careful footing. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Captain Cook Monument Trail trail page →Map, elevation profile, current weather, and OSM source.#2. Diamond Head Summit Trail
Diamond Head Summit Trail sits near Honolulu in Honolulu County and is rated hard — the #2 entry in a roster of hikes you don't take lightly. Tagged hard in OpenStreetMap. The route is well documented in OpenStreetMap, which is what put it on our radar — community-mapped routes tend to be the ones that get hiked enough to stay open. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Diamond Head Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#3. Diamond Head Summit Trail
Diamond Head Summit Trail sits near Honolulu in Honolulu County and is rated hard — the #3 entry in a roster of hikes you don't take lightly. Tagged hard in OpenStreetMap. It earns its ranking on the data, but trail conditions can change quickly after storms or fire seasons, so verify before you commit a full day. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Diamond Head Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#4. Diamond Head Summit Trail
Diamond Head Summit Trail sits near Honolulu in Honolulu County and is rated hard — the #4 entry in a roster of hikes you don't take lightly. Tagged hard in OpenStreetMap. Compared to similar trails in Hawaii, this route trades difficulty for either solitude or scenery — sometimes both. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Diamond Head Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#5. Diamond Head Summit Trail
Diamond Head Summit Trail sits near Honolulu in Honolulu County and is rated hard — the #5 entry in a roster of hikes you don't take lightly. Tagged hard in OpenStreetMap. What makes this one earn its spot on the list is the combination of mapped detail and the kind of through-and-through experience that justifies a longer drive. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Diamond Head Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#6. Diamond Head Summit Trail
Diamond Head Summit Trail sits near Honolulu in Honolulu County and is rated hard — the #6 entry in a roster of hikes you don't take lightly. Expect concrete surface on a genuinely demanding grade. Local trail-association reports tend to agree this is one of the better-maintained options in the area, which matters more on a hike of this length than on a quick walk. A paved surface makes this one of the more accessible options on the list — good for strollers, mobility aids, and wet-weather days. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Diamond Head Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#7. Ko'olau Summit Trail
Ko'olau Summit Trail sits near Kaneohe in Honolulu County and is rated hard — the #7 entry in a roster of hikes you don't take lightly. Tagged hard in OpenStreetMap. The route is well documented in OpenStreetMap, which is what put it on our radar — community-mapped routes tend to be the ones that get hiked enough to stay open. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Ko'olau Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#8. Ko'olau Summit Trail
Ko'olau Summit Trail sits near Kaneohe in Honolulu County and is rated hard — the #8 entry in a roster of hikes you don't take lightly. Expect ground surface on a genuinely demanding grade. It earns its ranking on the data, but trail conditions can change quickly after storms or fire seasons, so verify before you commit a full day. The natural-surface tread can get slick after rain and muddy in spring — pick a dry weather window if you have the flexibility. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Ko'olau Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#9. Koʻolau Summit Trail
Koʻolau Summit Trail sits near Waimanalo in Honolulu County and is rated hard — the #9 entry in a roster of hikes you don't take lightly. Expect ground surface on a genuinely demanding grade. Compared to similar trails in Hawaii, this route trades difficulty for either solitude or scenery — sometimes both. The natural-surface tread can get slick after rain and muddy in spring — pick a dry weather window if you have the flexibility. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Koʻolau Summit Trail trail page →Map, elevation profile, current weather, and OSM source.#10. Koolau Summit Trail
Koolau Summit Trail sits near Laie in Honolulu County and is rated hard — the #10 entry in a roster of hikes you don't take lightly. Expect dirt surface on a genuinely demanding grade. What makes this one earn its spot on the list is the combination of mapped detail and the kind of through-and-through experience that justifies a longer drive. The natural-surface tread can get slick after rain and muddy in spring — pick a dry weather window if you have the flexibility. Best attempted by hikers comfortable with long days, route-finding when the path gets faint, and weather that can turn fast. Not a casual outing. See full trail details, map, and current weather on OutsideAtlas for the most current information.
Open the Koolau Summit Trail trail page →Map, elevation profile, current weather, and OSM source.Planning your Hawaii trip
A few pieces of context are worth keeping in mind specifically for Hawaii. Year-round, but November-April brings wetter trails on windward sides; trade winds and rapid weather changes are constant. Flash floods in narrow valleys (especially Kaua'i and the Big Island), unstable volcanic rock, and exposed cliff-edge trails account for most rescues.
Always cross-reference the official land-manager page before driving out — closures, fire restrictions, and seasonal road access can change quickly. Our trail pages link directly back to the OpenStreetMap source so you can see the tags we're working from.
If you're new to hiking generally, our beginner's guide covers footwear, layering, and the day-pack basics. For safety planning on bigger objectives, the ten essentials guide is worth twenty minutes of reading.
More Hawaii hiking guides
If you found this useful, the rest of our Hawaii coverage continues below.
- Top 10 longest trails in Hawaii — Multi-day routes and through-hikes ranked by distance.
- Steepest trails in Hawaii — Hikes with the most elevation gain in the state.
- Best beginner hikes in Hawaii — Easy, well-marked trails for first-time hikers.
- Best national parks in Hawaii — Federal parks and recreation areas ranked.
- Best waterfall hikes in Hawaii — Trails leading to named falls, ranked by accessibility.
- Best dog-friendly hikes in Hawaii — Where leashed dogs are explicitly welcome.
- Best family hikes in Hawaii — Short, easy trails sized for kids and grandparents.
Rankings like this are starting points, not verdicts. Trail conditions change, new routes get tagged, and what was the toughest trail in Hawaii last year might not be next year. We refresh these articles when the underlying data shifts meaningfully.
Got a correction, a route we missed, or a question? Drop us a note via the contact page. We read every email and we'd rather hear it from you than miss it.
