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Oʻahu · Regional Guide

North Shore Oʻahu
Water Quality

Sunset Beach, Pipeline, Waimea Bay, Sharks Cove — live advisories and seasonal safety guide

Checking live advisories…
Winter Wave Danger — October through April
North Shore waves reach 20–40+ feet during winter swell season. Even when it looks “manageable,” rip currents and sudden set waves kill experienced swimmers every year. Lifeguards close beaches during large swells. Observe posted signs and flags.
Sunset Beach full guide →
North Shore Bacteria Risk — Overall
⚠ Historical rating — based on long-term testing data, not current conditions. The main hazard on the North Shore is waves, not bacteria.
Low Risk 1 / 5

The North Shore of Oʻahu has some of the cleanest ocean water in the state. The area has minimal urban development, no major rivers carrying agricultural runoff, and excellent open ocean flushing. DOH monitoring data consistently shows bacteria counts well below state health thresholds.

After significant rainfall in the Koʻolau and Waiʻanae mountain ranges, isolated bacteria spikes can occur near stream mouths — particularly near Haleiwa where Anahulu Stream empties into the ocean. The 72-hour rule applies after heavy rain. But in general, water quality is not the concern on the North Shore — waves are.

Based on: DOH monitoring data, North Shore watershed analysis, minimal upstream runoff sources

Summer vs Winter: What to Expect
☀️ Summer (May–Sept)
  • ✓ Ocean is flat and calm
  • ✓ Excellent snorkeling
  • ✓ Safe for families
  • ✓ Sharks Cove open
  • ✓ Water clarity 40–80 ft
  • ✓ Lifeguards on duty
❄️ Winter (Oct–Apr)
  • ✗ Waves 10–40+ feet
  • ✗ Swimming dangerous
  • ✗ Sharks Cove closed
  • ✗ Rip currents severe
  • ✓ World-class surf watching
  • ✓ Haleiwa town & food trucks
North Shore Beaches — Individual Ratings
🏖 Sunset Beach
1/5 bacteria risk · World-famous surf · Safe in summer only
1 / 5
🏖 Waimea Bay
1/5 bacteria risk · Rock jumping in summer · 30ft+ surf in winter
1 / 5
🏖 Sharks Cove (Pupukea)
1/5 bacteria risk · Best summer snorkel on North Shore · Summer only
1 / 5
🏖 Ehukai Beach (Pipeline)
1/5 bacteria risk · World’s most famous wave · Spectators only in winter
1 / 5
🏖 Haleiwa Beach Park
2/5 bacteria risk · Anahulu Stream mouth nearby · Protected harbor
2 / 5
Note on Haleiwa: Haleiwa Beach Park sits near the mouth of the Anahulu Stream and the small boat harbor. After rain, bacteria levels can spike here. The rest of the North Shore beaches have no nearby stream inputs and maintain consistently cleaner water.
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⚠️ 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 Department of Health Clean Water Branch before entering the water.

When in doubt, don’t go out.

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