Water quality ratings and safety guide for Kailua-Kona's best beaches
📍 Kailua-Kona to Kekaha Kai — North Kona, Hawaiʻi Island
North Kona's beaches range from the tourist-busy shores near Kailua-Kona town to remote, pristine stretches accessible only by foot or 4WD. The dry leeward climate means generally excellent water quality compared to windward coasts. From beginner-friendly snorkel parks to world-class remote beaches, North Kona has something for every ocean lover.
Kahalūū is the Big Island's most popular snorkeling beach — a fringing reef just steps from shore with sea turtles, humuhumunukunukuapuaʻa, and hundreds of fish. Water quality historically tests within baseline but the high visitor volume and proximity to the road can affect conditions. Avoid after heavy rain. Best visibility in the morning before wind picks up.
Full guide →Magic Sands Beach has white sand in summer and exposed rock in winter — hence the name. When the sand is present, it's one of the best swimming and bodysurfing beaches in Kona. Small, protected bay, minimal runoff. Moderate-low risk. Located just south of town, very accessible. Check if the sand is "in" before visiting.
Full guide →The Old Kona Airport State Recreation Area offers a long stretch of beach along the decommissioned runway. Good snorkeling on the rocky sections, calm swimming in sandy areas. Water quality historically tests within baseline with open ocean flushing. Minimal development — a local favorite for picnics and leisurely snorkeling.
Full guide →Honokohau is a secluded beach within Kaloko-Honōkōhau National Historical Park. Famous for Hawaiian monk seal and green turtle sightings on the sand. Water quality has a moderate risk due to nearby boat harbor runoff. The beach itself is pristine, but the harbor creates some water quality concerns. Worth visiting for wildlife, not just swimming.
Full guide →Makalawena is one of the most beautiful and uncrowded beaches on the Big Island. The rough 1.5-mile lava road (high-clearance vehicle needed) or 30-minute walk across lava field keeps crowds away. Stunning white sand, crystal-clear water, excellent snorkeling at the rocky ends. Water quality is outstanding. Bring everything — no facilities.
Full guide →Kua Bay (Maniniowali) is a picture-perfect white sand beach with bright turquoise water inside Kekaha Kai State Park. Paved road access makes it more popular than Makalawena, with a parking lot that fills early. Strong shore break in winter makes it more of a summer beach. Excellent water quality — one of the best on the Big Island.
Full guide →Top-rated experiences near this beach. Check water quality above, then plan your trip.
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Hawaii’s Department of Health monitors approximately 57 beaches statewide through regular bacteria testing. However, with over 300 swimmable beaches across the islands, many popular spots have no regular testing program. Water quality varies significantly based on rainfall, stream proximity, coastal development, and ocean circulation patterns.
After heavy rain, streams and storm drains carry bacteria, sewage, pesticides, and sediment into coastal waters. The DOH recommends staying out of the ocean for at least 48 to 72 hours after heavy rain, even if the water appears clear. Brown or murky water is a visible sign of contamination, but bacteria can be present in clear water near stream mouths.
This site aggregates data from six sources — DOH advisories, USGS stream monitoring (25 stations), NOAA tide and temperature data, NDBC wave buoys, NWS weather alerts, and City & County of Honolulu water testing — to provide a more complete picture than any single source.
The 72-hour rule is the standard guideline from the Hawaii Department of Health: avoid swimming for at least 72 hours after heavy rain stops, especially near stream mouths, canal outlets, and areas with brown or discolored water. This applies to all beaches across all islands.
Bacteria from urban runoff, agricultural land, and aging cesspool systems enters the ocean through streams and storm drains. Hawaii has approximately 88,000 cesspools — more than any other state — many of which leak untreated sewage into groundwater that eventually reaches the coast. Beaches near known cesspool contamination areas carry higher risk, particularly after rainfall.
⚠️ Important Disclaimer
Safe to Swim Hawaii is independent, not affiliated with the Hawaii DOH. Ratings are estimates, not real-time measurements.
Verify with the Hawaii DOH Clean Water Branch.
This site does not recommend or advise anyone to swim at any beach. We share government data and geographic analysis so you can make your own informed decisions. By using this site you accept full responsibility for your own safety. See our Terms of Use for full details.
When in doubt, don't go out. 🤙