What to expect for water quality, rainfall, and ocean conditions
The Waimea River carries runoff from the surrounding valley. Advisory risk increases with rainfall. Check for brown water near the river mouth.
November brings serious winter surf to Waimea Bay. Large north swells create massive waves and dangerous currents. Swimming becomes hazardous or impossible on big swell days. Brown water advisories increase.
Winter brings massive north swells to Waimea Bay, some of the largest rideable waves on Earth. The bay is closed to swimming during big surf events. Powerful currents and shore break make the water extremely dangerous.
Moderate. Late fall brings fewer visitors before the holiday rush begins.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. In november, this is especially important as wet-season storms can produce heavy rainfall and significant runoff.
When conditions are clear, Waimea Bay 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. 🤙