What to expect for water quality, rainfall, and ocean conditions
Dry season brings reduced rainfall to the windward coast. Waimanalo Beach water quality is generally good during summer months, especially away from stream mouths.
April rainfall drops to about 2 inches on the windward coast. Conditions improve notably. Waimanalo's long beach means you can often find sections away from stream mouths with better water quality.
Transitional conditions with variable trade wind swells. Waimanalo faces east, so it catches more wind swell than south or north-facing beaches. Water temperature shifts between seasonal ranges. Generally swimmable.
Moderate. The shoulder season between spring break and summer offers a good balance of pleasant weather and manageable crowds.
The Hawaii Department of Health recommends staying out of the ocean for at least 72 hours after heavy rain. In april, rainfall is less frequent but individual storms can still produce contaminated runoff.
When conditions are clear, Waimanalo 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. 🤙