Beach · Honolulu County · HI
Is Waimanalo Beach Co Park safe to swim?
No advisory or algae bloom reported for this water today.
Updated July 19, 2026 · Hawaii beach program (EPA BEACON)
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What's in the water at Waimanalo Beach Co Park right now
As of July 19, 2026, Waimanalo Beach Co Park in Honolulu County, Hawaii is clear to swim. Blue-green algae are not currently monitored at this water. No fecal-bacteria advisory is posted (state beach program). Rainfall over the past week totaled 0.7 in, which can wash bacteria and nutrients into the water.
Blue-green algae at Waimanalo Beach Co Park
Waimanalo Beach Co Park is a lake in Honolulu County, Hawaii. Blue-green algae are not currently monitored at this water.
Blue-green algae (cyanobacteria) blooms are most common from midsummer into early fall, when the water is warm, calm, and rich in nutrients from runoff. They can produce toxins that make people sick and can be rapidly fatal to dogs, so skip water that looks green, scummy, or like spilled paint, and keep children and pets out of it.
Frequently asked: swimming in Waimanalo Beach Co Park
- Is it safe to swim in Waimanalo Beach Co Park right now?
- Waimanalo Beach Co Park is clear to swim today. Blue-green algae are not currently monitored at this water. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
- Does Waimanalo Beach Co Park have blue-green algae (cyanobacteria)?
- Blue-green algae are not currently monitored at Waimanalo Beach Co Park. Watch for green, blue-green, or paint-like scum and avoid the water if you see it.
- Can dogs swim in Waimanalo Beach Co Park?
- No bloom is detected at Waimanalo Beach Co Park today, but dogs are much more vulnerable to blue-green algae than people, and blooms can form within hours. Always keep dogs away from water that looks green, scummy, or discolored, and rinse them off after swimming.
- How many Hawaii lakes and beaches have swim advisories today?
- Today, 0 Hawaii waters are under a swim advisory and 106 more warrant caution, out of 402 monitored waters SwimZone tracks in the state.
- How is Waimanalo Beach Co Park's water quality measured?
- SwimZone builds this read from EPA CyAN satellite imagery for blue-green algae, official beach and fecal-bacteria advisories where a program monitors Waimanalo Beach Co Park, and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.