Kona side vs Hilo side: two completely different experiences on one island.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. The Kona (west) side is dry with clean beaches. The Hilo (east) side gets 130+ inches of rain per year. Kohala Coast is the driest area in the state with less than 10 inches annually.
The Big Island (Hawaiʻi Island) is larger than all other Hawaiian islands combined. Its coasts range from bone-dry lava deserts to the wettest place in the United States. The island is divided by five volcanic mountains that create dramatically different microclimates.
Climate: Less than 10 inches of rain per year. Driest area in the state.
Character: Luxury resorts built on ancient lava flows. Each resort has its own beach cove.
Water quality: Consistently excellent. Minimal runoff, strong ocean flushing.
Key beaches: Hapuna, A-Bay, Kaunaʻoa Bay. Full guide →
Climate: Dry, 15-25 inches of rain per year.
Character: Kailua-Kona town, Aliʻi Drive, small pocket beaches on lava coast.
Water quality: Mixed. Kahaluʻu has 92% bacteria failure. Magic Sands and open-coast beaches are cleaner.
Key beaches: Kahaluʻu, Magic Sands. Full guide →
Climate: 130+ inches of rain per year. One of the wettest cities in the US.
Character: Rocky coastline, few sandy beaches. Waterfalls, rainforest, botanical gardens.
Water quality: Frequent runoff. Not a primary swimming coast. Richardson Ocean Park and Carlsmith Beach Park have freshwater spring-fed pools.
Character: Remote, undeveloped southern tip of the island. Black and green sand beaches.
Key attractions: Punaluʻu Black Sand Beach (sea turtles), Papakōlea Green Sand Beach (2.5-mile hike).
Warning: Strong currents at most Kaʻū beaches. Not for casual swimming. Cold freshwater springs at Punaluʻu.
Character: Dramatic sea cliffs, no beach access. Waipiʻo Valley has a black sand beach at the bottom of a steep valley.
Swimming: Not recommended. Waipiʻo Beach has dangerous rip currents and river-mouth contamination. This coast is for scenic viewing, not swimming.
Top-rated experiences in the area.
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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 testing data and geographic analysis. They are not real-time measurements and may not reflect current conditions.
Always verify current water quality conditions with the Hawaii DOH Clean Water Branch before entering the water.
When in doubt, don't go out. 🤙