Water quality, swimming conditions, and beach guide for Mahiʻula and Makalawena
📍 Highway 19, ~2 miles north of Kona Airport, Big Island
Kekaha Kai State Park sits on the Big Islandʻs extremely dry North Kona Coast, one of the least-rainy areas in the entire state. Annual rainfall here is often under 10 inches, meaning essentially zero agricultural or stormwater runoff reaching the ocean. Strong open-ocean flushing by consistent tradewind swells keeps the water crisp and clear.
Mahiʻula Beach, the parkʻs main beach, consistently shows excellent water quality year-round. The remote location also means fewer people, which limits human contamination impact. Makalawena Beach, requiring a hike to access, is even more pristine — one of the cleanest-water beaches on the entire island.
Based on: Extremely dry North Kona climate, no stream input, remote location, strong open-ocean flushing
The DOH recommends staying out of the ocean for at least 72 hours after heavy rain. This area rarely receives significant rainfall, but on the rare occasions it does, wait until the water visibly clears before swimming. Check our rain guide for more detail.
The parkʻs main beach — a wide white-sand crescent backed by kiawe trees. Accessible by car (rough road). Good swimming when calm; morning hours before tradewinds. Snorkeling along the rocky edges excellent. Sea turtles common. Portable toilets at the parking area.
A hidden gem reachable only by a 1.5-mile hike through black lava fields from the Mahiʻula parking area. Wide, bright white sand backed by ironwood trees. Consistently uncrowded. Crystal-clear water, excellent snorkeling. Bring everything — absolutely no facilities. Worth every step of the hike.
The park contains rare anchialine ponds — landlocked brackish pools connected to the ocean through underground lava tubes. These support unique Hawaiian fauna including the ʻōpaeʻula (endemic red shrimp). Do not enter the ponds — they are ecologically sensitive. View from the shore.
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⚠️ Important Disclaimer
Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health or any government agency. Water quality ratings are estimates based on publicly available data. They are not real-time measurements.
Always verify with the Hawaii Department of Health Clean Water Branch before swimming.
When in doubt, don't go out. 🤙