The Big Island has two very different coastlines. Here's how to decide which side to base yourself on — and where to find the best water quality.
If classic beach vacation — white sand, calm water, snorkeling, sunshine — is your goal, the Kona (west) side is the clear winner. The Kohala Coast north of Kona has the Big Island's best beaches. Hilo is spectacular for waterfalls, volcanoes, and culture, but its beaches are rocky, often rainy, and prone to brown water advisories. Stay in Kona; day-trip to Hilo.
Rainfall data approximate; varies significantly by elevation and micro-location.
This is where the two sides diverge most dramatically — and where it matters most for swimmer safety.
The dry leeward coast receives little rain and has no major rivers draining to the ocean. With minimal storm runoff and strong offshore trade winds that keep coastal waters well-flushed, the Kohala Coast and Kona town beaches have historically excellent water quality. Bacterial advisories are rare. When one does occur, it's typically localized and brief.
Hilo's heavy, year-round rainfall means streams and rivers are frequently flooded, carrying sediment and bacteria to nearshore waters. The Wailuku River, Wailoa River, and numerous smaller streams all drain into Hilo Bay and nearby beaches. Brown water advisories are common in Hilo after any significant rain event — which can happen multiple times per week.
At any Hilo-side beach, apply the 48-hour rule: avoid ocean contact for at least 48 hours after significant rainfall. This applies even to popular spots like Richardson Ocean Park. Always check Hawaii DOH for current advisories before swimming.
The Big Island is large — driving from Kona to Hilo takes about 2–2.5 hours via Saddle Road (the faster route). A Kona base lets you enjoy beach days on the west side while making day trips to volcanoes, Hilo town, and waterfalls on the east side.
Top-rated experiences near this beach. Check water quality above, then plan your trip.
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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.
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. 🤙