Safe to Swim Hawaii

Hawaii Beach Water Quality Data Hub

Every Hawaii beach water-quality resource in one place — live DOH advisories, Surfrider BWTF community testing across 100+ sites, year-over-year trend analysis, sewage-spill tracking, stream-mouth contamination data, and 14-day forecasts.

Live Status — What's Happening Right Now
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Hawaii Water Quality Today
Live DOH advisories statewide, refreshed every 15 minutes. Six data sources combined.
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Cleanest Hawaii Beaches Right Now
Statewide leaderboard ranked by 30-day advisory-free record. Includes Surfrider BWTF context.
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Brown Water Advisory — Live Status
Active brown-water advisories across all islands, plus the 72-hour rule explained.
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Hawaii Sewage Spills Today
Live DOH sewage-spill tracker plus recent 90-day history. Currently 2 active spills.
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Community Testing — Beyond DOH Coverage
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Hawaii Citizen Water-Quality Testing
Surfrider Foundation Blue Water Task Force tests 103 Hawaii beaches that DOH doesn't routinely visit. Per-island coverage with latest readings.
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Why Molokaʻi & Lānaʻi Aren't Tested
The honest coverage gap: no agency tests Molokaʻi or Lānaʻi waters. Who's working to change that.
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Trend + Forecast — Direction of Change
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Hawaii Water Quality Forecast
14-day trend per island vs the 14 days before, plus 7-day NOAA NWS rainfall outlook for each island's primary tourist coast.
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Is Hawaii's Beach Water Getting Cleaner or Dirtier?
Year-over-year DOH data: last 365 days vs the 365 before. Statewide and per-island trend analysis.
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Understanding the Data — Why It's Like This
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Why Hawaii Water Turns Brown After Rain
20 of 24 Hawaii stream/river mouths Surfrider tests exceed the 130 BAV threshold. Worst: 6,586 MPN at Kaupuni Stream — 51× the action value. The 200m distance rule and the science of stream-driven contamination.
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Dry Side vs Wet Side Hawaii — Where to Stay
Leeward beaches average ~15 MPN; windward stream mouths average ~1,500 MPN. Per-island data tables and the leeward-vs-windward water-quality gap.
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Hawaii Cesspool Problem
88,000 active cesspools across the state, the 2050 phase-out deadline, and how cesspool effluent reaches the ocean.
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Swimming After Rain in Hawaii
The 72-hour rule and 4-tier post-rain recovery table. Why even leeward beaches need wait time.
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By Island — Cleanest Beaches Now
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Cleanest Oʻahu Beaches Right Now
Live ranking of 12 tracked Oʻahu beaches plus Surfrider BWTF readings.
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Cleanest Maui Beaches Right Now
Live ranking of 6 tracked Maui beaches plus BWTF Maui chapter readings.
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Cleanest Kauaʻi Beaches Right Now
Live ranking of 6 tracked Kauaʻi beaches plus BWTF Kauaʻi chapter readings.
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Cleanest Big Island Beaches Right Now
Live ranking of 7 tracked Big Island beaches. Kohala Coast leads — historically the cleanest stretch in Hawaiʻi.
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Cleanest Hawaiian Island
Cross-island ranking of which Hawaiian island has the cleanest beach water on average.
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Trip Planning — Where to Stay if Water Quality Matters
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Where to Stay in Hawaii with Kids
Family-first resort areas ranked by water quality: Kohala Coast, South Maui, Ko Olina, Poʻipu.
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Which Island for a First Visit?
First-timer planning ranked by both convenience and water quality. Two-ranking format so you pick your weighting.
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Best Family Beaches in Hawaii
Calm-water family beaches ranked across all islands, with water-quality context.
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Daily Updates
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Daily Hawaii Water Quality Report
A new water-quality report every day — story-of-the-day from the pipeline. Trend flips, milestones, and current outlook.
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After-Rain Beach Picker — Interactive Tool
Three-question decision tool: tell us your island, when it last rained, and where you are — get personalized recommendations.
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Underlying Sources

All data on this site is sourced from authoritative public agencies and community programs:

Refresh cadence: live for DOH advisories (every 15 min via /.netlify/functions/api), weekly for BWTF data (Saturday mornings via cron), daily for forecast + statewide aggregates.

Frequently Asked
What's the difference between Hawaii DOH and Surfrider BWTF data?

DOH (Hawaii Department of Health Clean Water Branch) runs the official state monitoring program at roughly 47 stations across O'ahu, Maui, Kaua'i, and Big Island. BWTF (Surfrider Foundation Blue Water Task Force) is a volunteer-run citizen-science program testing 103 additional Hawai'i sites across Kaua'i, O'ahu, and Maui chapters. Both compare against the same 130 MPN/100mL Beach Action Value threshold but use different lab methods (DOH culture-based CFU vs BWTF IDEXX Enterolert MPN). Together, the two programs cover ~150 unique sites — roughly 3× what DOH alone monitors.

Are Moloka'i and Lāna'i tested?

No. Neither DOH nor Surfrider BWTF has active routine bacteria-testing stations on Moloka'i or Lāna'i. Both islands receive island-wide Brown Water Advisories during heavy storm events (driven by visible runoff observations), but no per-beach bacteria readings exist. See the full coverage-gap explainer.

How often does this site update?

Live DOH advisories every 15 minutes on the live-status pages. BWTF data weekly via cron (Saturday mornings). Per-beach 30-day history widgets, leaderboards, statewide and per-island trend pages, NOAA forecast outlook, and the YoY comparison all rebuild daily at 5:23 AM HST.

Is Hawai'i's water getting cleaner or dirtier overall?

As of April 2026, the answer is dirtier. The YoY trend page shows Hawaii's advisory-days metric is up 47.2% in the last 365 days vs the prior year, driven primarily by the persistent 2026 Kona Low storm cycle.

Does "low advisory frequency" mean it's safe to swim?

No. We never label any beach as safe — water-quality advisory data is one factor among several. Physical hazards (rip currents, shore break, surf, marine life) vary by beach and are independent of bacteria readings. Always check the individual beach page for current DOH advisories, posted warning signs, and lifeguard guidance before swimming.

Disclaimer: Safe to Swim Hawaii is an independent passion project — not affiliated with the Hawaii Department of Health, Surfrider Foundation, or any government agency. We aggregate publicly available data so individuals can make their own informed decisions. This is not a swim recommendation. Always check current Hawaii DOH advisories at the official source before entering the water.