What to expect for water quality, rainfall, and ocean conditions
Even in the dry season, Nawiliwili Stream continues carrying bacteria to Kalapaki Beach. Reduced rainfall improves conditions but the stream's contamination is persistent. Swim away from the stream mouth.
June is drier at about 1.5 inches. Reduced rainfall means less runoff through Nawiliwili Stream, though the stream's bacteria loading is persistent. Harbor boat traffic continues. Water quality is at its seasonal best.
Summer brings calm conditions to Kalapaki Beach. The bay is sheltered from trade winds by the harbor breakwater. Water is warm (79-80°F). The protected bay shape makes it suitable for swimming, kayaking, and SUP.
High. Summer is peak family travel season with school holidays. Beaches are busy from mid-morning through sunset.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. In june, rainfall is less frequent but individual storms can still produce contaminated runoff.
When conditions are clear, Kalapaki Beach has excellent ocean activities. Check the water quality above, then book with confidence.
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Safe to Swim Hawaii provides water quality information based on publicly available DOH data and seasonal patterns. This is not medical or safety advice. Always check current conditions, obey posted signs, and use your own judgment before entering the ocean. Privacy Policy
⚠️ 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. 🤙