What to expect for water quality, rainfall, and ocean conditions
Hapuna Beach has one of the lowest advisory rates in Hawaii. The dry climate and lack of stream discharge mean water quality is consistently excellent.
September remains excellent at Hapuna. The dry Kohala Coast sees no significant rain. Ocean conditions are calm. Fewer visitors than peak summer provide a more relaxed experience.
Summer brings calm conditions to Hapuna with gentle shore break. Water is crystal clear and warm (79-80°F). The wide white sand beach and calm water make this the Big Island's premier swimming beach.
Moderate to low. Fall shoulder season offers fewer tourists while conditions remain good. This is one of the best value periods for visiting Hawaii.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. In september, rainfall is less frequent but individual storms can still produce contaminated runoff.
When conditions are clear, Hapuna Beach has excellent ocean activities. Check the water quality above, then book with confidence.
Tours listed via Viator and GetYourGuide. Safe to Swim Hawaii may earn a commission if you book, at no extra cost to you.
Free alerts when water quality changes at your beach — brown water advisories, bacteria warnings, and all-clear notices.
No spam. Just safety alerts for your trip.
500+ beaches and 25+ hotels across all 6 islands
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. 🤙