August on Big Island means peak-season prices and the fullest beaches of the year. Mainland families on school break pack the Kohala Coast resorts between Waikoloa and Mauna Lani, and Kailua-Kona's Ali'i Drive fills with rental cars by mid-morning. The coastal weather along the leeward side compensates, though. Warm, dry days in the high 20s Celsius (low to mid 80s Fahrenheit) and an ocean temperature around 26°C (79°F) make this one of the strongest months for snorkeling and manta ray night dives.
What catches first-time visitors off guard is how much cooler this island runs compared to Oahu or Maui. Big Island rises from sea level to the summit of Mauna Kea at 4,207 meters (13,802 feet), giving it the most extreme topographic range of any Hawaiian island. Step off the plane in Kona and tropical heat presses against your skin. Drive 45 minutes to Waimea's ranch country and you'll reach for a fleece. Continue to Volcano Village and evenings drop toward single-digit Celsius readings. No other island in Hawaii demands this kind of packing range.
Hurricane season is technically active, though direct landfalls on the islands remain rare. A more persistent issue is vog, the volcanic haze that Kilauea sends across the Kona coast on still afternoons. It leaves a milky sky and a faint sulfur taste that visitors with asthma should take seriously before booking. Hilo, on the windward side, collects the majority of the island's rainfall, while the Kona coast can go 7 or 8 days straight without a cloud.
Why visit in August
- Calmest ocean conditions of the year along the Kona coast. Summer swells rarely top 0.5 meters (2 feet), making Kealakekua Bay and similar marine reserves accessible for snorkeling nearly every day of the month.
- Peak reliability for manta ray encounters. Tour operators working the Keauhou coast report sighting rates above 90% on clear August nights, thanks to calm surface conditions and warm water drawing mantas to nearshore feeding grounds.
- The leeward Kona coast stays reliably dry in August. When rain does come, it typically passes through in 10-15 minutes and leaves the rest of the afternoon clear.
- Green sea turtles haul out regularly at Punalu'u Black Sand Beach through summer. August is one of the most consistent months for spotting them resting on the dark sand from a respectful distance.
Worth knowing
- Accommodation prices reach their annual peak. Kohala Coast resort rates in August can run 30-50% higher than shoulder-season months like October or May.
- Vog episodes can wash out views of Maui and Lanai from the Kona coast, dim sunset photography, and irritate sensitive airways. The haze persists until trade winds return, which might take several days.
- Parking lots at Hapuna Beach, the Kilauea crater rim overlook, and Akaka Falls fill by 9-10 AM on most mornings. Early arrival becomes a requirement, not a preference.
- No whale watching. Humpbacks are present only from December through April, making August the wrong time if cetaceans are a primary draw.
Best for
Think twice if
Big Island's August weather varies more by elevation than by date. The island-wide average high of 18.3°C (65°F) and low of 8.2°C (47°F) reflect terrain that rises from tropical coast to alpine summit within 60 km (37 miles). Humidity averages 67%, concentrated at lower elevations near the coast. Rainfall reaches 87mm spread across 11 days, falling predominantly on the windward Hilo side. The leeward Kona coast typically sees fewer than 4 rainy days during the month, and those tend to be brief afternoon showers. Above 3,000 meters (9,800 feet), overnight frost remains possible even in midsummer.
Seasonal caution
- Central Pacific hurricane season runs June through November. Direct hits are statistically rare, but tropical systems can produce heavy rain, high surf, and road closures with 2-3 days' notice. Monitor the Central Pacific Hurricane Center forecasts if a system is tracking west.
- Vog from Kilauea's eruptions can elevate sulfur dioxide concentrations over the leeward coast during low-wind periods, triggering symptoms in people with asthma or COPD. The Hawaii Department of Health publishes daily vog forecasts worth checking before outdoor plans.
- UV index readings of 11-12 are common at this latitude, even on hazy days. Hawaii sits near 20°N, and August's near-overhead sun angle makes unprotected exposure dangerous within 15-20 minutes.
Year-round climate
Averages from the last 5 years.
| Month | Avg high (°C) | Avg low (°C) | Rainfall (mm) |
|---|---|---|---|
| Jan | 15 | 6 | 72 |
| Feb | 14 | 5 | 85 |
| Mar | 14 | 6 | 111 |
| Apr | 15 | 6 | 91 |
| May | 16 | 7 | 77 |
| Jun | 17 | 8 | 25 |
| Jul | 18 | 8 | 54 |
| Aug | 18 | 8 | 87 |
| Sep | 18 | 8 | 53 |
| Oct | 17 | 8 | 76 |
| Nov | 16 | 7 | 86 |
| Dec | 15 | 7 | 65 |
Best things to do in August
Manta Ray Night Snorkel off Keauhou
water sportsSnorkelers float face-down on the surface holding a light board while reef manta rays, some with wingspans over 3 meters (10 feet), glide beneath to feed on plankton drawn by the lights. The salt water is warm enough that most people don't need a wetsuit.
August's calm surface conditions make the zodiac ride smoother and underwater visibility clearer than winter months. Sighting rates are among the highest of the year.Booking tipBook 2-3 weeks ahead. Operators cap group sizes at 10-12 snorkelers, and August evening slots sell out fast.
Stargazing from Mauna Kea
natureThe Visitor Information Station at 2,800 meters (9,200 feet) runs free evening stargazing programs with telescopes set up by volunteer astronomers. The cold, dry air at altitude produces exceptional seeing conditions. On clear nights, the Milky Way arcs overhead with a clarity most mainland observers never experience.
Clear summer skies and low humidity at elevation offer some of the year's best observing conditions. The Perseid meteor shower peaks around August 12, adding a reliable show.Booking tipArrive by 6 PM to acclimate before sunset. The road above the VIS to the summit requires a 4WD vehicle. Bring all your warm layers.
Snorkeling at Kealakekua Bay
water sportsThis marine sanctuary on the South Kona coast holds some of the clearest water in the state. Spinner dolphins frequent the bay in the morning hours, and the coral reef along the monument side teems with tropical fish. The underwater visibility on a calm August day can reach 30 meters (100 feet).
August brings the calmest water conditions of the year to this west-facing bay. The protected cove is at its most accessible, with minimal swell disruption.Booking tipKayak permits through the state DLNR fill months ahead for summer dates. A guided boat tour is the realistic alternative for most visitors.
Hiking the Kilauea Iki Trail at Hawai'i Volcanoes National Park
hikingThe trail descends through a fern-filled rainforest into the crater and crosses the solidified surface of a lava lake that last erupted in 1959. Steam vents still rise through cracks in the rock, and the air carries a faint mineral smell. The moderate loop is one of the park's most rewarding hikes.
The park's elevation keeps August temperatures comfortable while coastal hikes become uncomfortably hot. Drier summer weather means fewer muddy sections on the rainforest descent.Booking tipNo booking required, but arrive before 10 AM to find parking near the Kilauea Iki Overlook trailhead.
Swimming at Hapuna Beach State Recreation Area
beachA wide, white-sand beach on the Kohala Coast with gentle entry and lifeguard coverage. The sand is soft and fine, unusual for a volcanic island. Facilities include restrooms, showers, and a shaded picnic area. The beach runs roughly 400 meters (0.25 miles) along a crescent-shaped bay.
Summer brings flat to minimal surf, making the full stretch of the beach safe for swimming. Winter months produce shore breaks strong enough to cause spinal injuries, but August conditions tend to be gentle.Booking tipThe parking lot fills by 9-10 AM in August. Arrive early or plan for the overflow lot, which adds a short downhill walk.
Exploring Waipi'o Valley
hikingA steep-walled valley on the Hamakua Coast with a black sand beach, taro farms, and waterfalls fed by upslope streams. The overlook at the top provides one of the island's most photographed views. The road down is paved but extremely steep, with grades exceeding 25%.
August falls in the drier stretch for the Hamakua Coast, so the descent road is less slippery than winter months and the valley floor is more passable on foot.Booking tipIf you don't have a 4WD vehicle, guided tours run daily from the overlook near Honoka'a. Walking down and back up is doable but strenuous.
What to eat in August
In season: fruit
Hawaiian Mango
South Kona orchards hit peak sweetness in August. Hayden and common varieties appear at Hilo and Kona farmers markets for a fraction of mainland supermarket prices. The flesh is warm and fragrant after a day in the sun.
Lilikoi (Passion Fruit)
Passion fruit grows wild across the island's lower elevations, and August vines hang heavy with ripe fruit. The tart, fragrant pulp goes into fresh juice, lilikoi butter, and chiffon pie at bakeries around Hilo.
On menus now
Poke
Fresh ahi tuna runs strong in Hawaiian waters through summer. August poke at roadside counters in Kona and Hilo uses fish that was likely in the water that same morning. Look for shoyu, limu, and spicy mayo styles.
Street food peaks
Shave Ice
Not a seasonal food in the strict sense, but August heat makes it a near-daily ritual. Big Island shops tend to use cane sugar syrups and fresh lilikoi or mango over artificial flavors. Some add a scoop of haupia (coconut pudding) at the bottom.
In markets
Ulu (Breadfruit)
Summer is peak ulu season on the island. Restaurants in Hilo and along the Kohala Coast increasingly feature breadfruit fries, baked ulu, and poi-like preparations as a starchy side dish. Trees heavy with fruit line the roads through Captain Cook.
Regular events in August
Admission Day (Statehood Day)Free
Hawaii's state holiday commemorating August 21, 1959 statehood. Government offices and some businesses close. The day carries mixed significance for Native Hawaiians, and visitors should be aware it is a sensitive topic, not universally celebrated.
Third Friday of August (August 21 in 2026)Hawaiian International Billfish TournamentFree
One of the oldest sportfishing tournaments in the Pacific, running since 1959. International teams fish for Pacific blue marlin off the Kona coast over 5 days. Afternoon weigh-ins at Kailua Pier draw spectators who gather to see the day's catch hoisted on the scale.
Late July through early August (5-day tournament)After Dark in the Park at Hawai'i Volcanoes National ParkFree
Monthly evening program at Kilauea Visitor Center featuring talks by scientists, cultural practitioners, and park staff. Topics rotate between volcanology, Hawaiian ecology, and cultural history. Held in a small auditorium with limited seating.
One Tuesday evening per month, typically the third TuesdayBest places this August
Pu'uhonua o Honaunau National Historical Park
historical siteThe reconstructed temple complex and royal grounds sit on the South Kona coast. August's dry weather and morning calm make the tide pools around the park's shoreline especially clear. Green sea turtles often rest on the lava shelf along the 1871 Trail, and the wooden ki'i (carved images) catch low-angle morning light well for photography.
South KonaAkaka Falls State Park
natureThe 135-meter (442-foot) waterfall drops into a gorge framed by bamboo and tropical vegetation on the Hamakua Coast, about 20 minutes north of Hilo. August offers a drier approach on the paved loop trail, though the falls still run strong from upslope moisture. The air in the gorge is cool and damp, a sharp contrast to the coast.
Hamakua CoastWaimea (Kamuela) Town
townThis ranch town at roughly 800 meters (2,600 feet) elevation runs cooler than the coast and feels far removed from the resort strip. The Saturday morning Waimea Town Market brings ranchers, farmers, and food vendors. Parker Ranch, one of the oldest and largest cattle ranches in the United States, sits at the edge of town and offers heritage tours.
WaimeaSouth Point (Ka Lae)
landmarkThe southernmost point in the United States. A windswept cliff edge with views of rough open ocean and a rugged, empty coastline. August trade winds tend to be lighter than winter months, making the drive down the narrow access road and the exposed clifftop walk more comfortable. The nearby Papakolea green sand beach is a 45-minute hike each way.
Ka'uKona Coffee Living History Farm
museumA working coffee and macadamia farm preserved to show early 20th-century Japanese immigrant agriculture along the Kona coffee belt. The earthy aroma of roasting macadamia nuts fills the property. Located at about 450 meters (1,500 feet) elevation near Captain Cook, the farm sits a few degrees cooler than the coast and offers a tangible link to the region's agricultural history.
Captain Cook
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Insider tips
If you're staying on the Hilo side or in the Puna district, prepare for coqui frogs. These tiny tree frogs produce a piercing, two-note call that runs all night at roughly 90 decibels measured from close range. Some visitors find it charming. Others can't sleep. Check accommodation reviews specifically for frog noise before booking.
The Hilo Farmers Market on Wednesday and Saturday mornings is the real deal, not a tourist staging. Local vendors sell rambutan, starfruit, dragon fruit, and whatever else is in season at well below mainland supermarket prices. Saturday is the larger market. Arrive before 9 AM for the best selection.
LGBTQ+ travelers will find the island welcoming. Big Island scores 8.5/10 for LGBTQ+ friendliness (sourced from TTDI's editorial rubric). Hawaii's legal protections are among the strongest in the U.S., and both the Kona and Hilo communities are small but inclusive.
Check the Hawaii Department of Health vog forecast before planning Kona coast outdoor activities. On heavy-vog days, the air quality on the Hilo side and at higher elevations tends to stay clean because trade winds push the haze leeward.
Gas stations get sparse outside Kailua-Kona and Hilo. Fill your tank whenever you pass a station in Waimea, Captain Cook, or Volcano Village. The stretch from South Point back to Kona drains fuel faster than expected on the uphill return.
Avoid these mistakes
- Packing only beach clothes. Big Island's elevation range means you might need layers from boardshorts to fleece in the same afternoon. Visitors who drive from the coast to the Mauna Kea stargazing program in shorts and rubber slippers end up genuinely cold and miserable above the cloud line.
- Trying to drive the entire island in one day. The loop covers roughly 380 km (236 miles), but speeds rarely exceed 90 km/h (55 mph) on the winding two-lane coastal roads. Plan at least 3 days to cover the major regions without turning the trip into a windshield tour.
- Scheduling a midday visit to Hawai'i Volcanoes National Park. Afternoon clouds roll in over the Kilauea crater rim most days by 1-2 PM, obscuring the view entirely. Morning visits before 10 AM offer the clearest conditions and the emptiest parking lots.
- Skipping the rental car reservation until the last minute. August demand exhausts the island's limited fleet. Public transit on Big Island is minimal, and rideshare coverage barely extends past Kailua-Kona.
Practical tips for August
Book rental cars and Kohala Coast accommodation 3-4 months before your August arrival. Kealakekua Bay kayak permits through the state DLNR sell out even earlier for summer dates. Public transit on the Hele-On Bus system runs limited routes and schedules, so a car is close to mandatory for reaching most attractions. Grocery prices on Big Island tend to run noticeably above mainland averages, so stocking up at the Costco in Kailua-Kona or the Target in Hilo early in your trip helps keep food costs manageable. Most restaurants do not require reservations, but the handful of higher-end options along the Kohala Coast fill up during August. Tipping follows standard U.S. practice at 18-20%. The island operates on Hawaii Standard Time (HST, UTC-10) year-round with no daylight saving adjustment, putting it 6 hours behind U.S. Eastern time in August.
FAQ
Is August a good time to visit Big Island?
August is a good time for beach and ocean activities, particularly along the Kona coast, where water conditions are among the calmest and warmest of the year. The trade-off is peak pricing and higher visitor density at popular spots. If your schedule allows flexibility, the shoulder months on either side of summer offer similar coastal weather with noticeably lower costs and thinner crowds.
What is the weather like on Big Island in August?
It depends heavily on where you are on the island. The leeward Kona coast tends to be warm and dry with infrequent brief showers. The windward Hilo side receives regular rainfall, sometimes daily. Elevation changes everything. You can start the day warm at the beach and end it needing a jacket at Volcano Village or on Mauna Kea. Pack for multiple climates rather than one.
Is Big Island crowded in August?
The Kohala Coast resort strip, Hapuna Beach, and Kailua-Kona's waterfront are noticeably full. Hawai'i Volcanoes National Park sees some of its highest visitor numbers. That said, Big Island covers over 10,000 km² (4,028 sq mi), and less-visited areas like the Hamakua Coast, the South Kona coffee belt, or the Ka'u district feel uncrowded even in the peak of summer.
Can you see lava on Big Island in August?
Kilauea's surface activity varies and is not guaranteed on any visit. Hawai'i Volcanoes National Park is open year-round, and the park's website posts real-time eruption updates. Even without active surface flows, the steam vents, the Kilauea Iki crater crossing, and the Thurston Lava Tube (Nahuku) are worth the trip to the park.
Do I need a rental car on Big Island in August?
Effectively, yes. The Hele-On Bus runs limited routes on a reduced schedule, and rideshare apps have minimal coverage outside of central Kailua-Kona. Most beaches, trailheads, and attractions are spread across the island's full circumference. Walking or busing between them is not realistic for most itineraries.
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