Real-time water quality information for Hawaii’s beaches and hotels.
Safe to Swim Hawaii helps tourists and residents make informed decisions about ocean swimming by answering one question: will I get sick from the water?
The site pulls real-time advisory data from the Hawaii Department of Health Clean Water Branch and combines it with historical bacteria testing data to give every beach a risk rating. We cover brown water advisories, sewage spill notifications, beach advisories, and bacteria exceedances across all Hawaiian islands.
No other resource combines live DOH advisories with historical bacteria data in a format designed for people planning a beach day — not scientists or regulators.
Every 15 minutes, we check the Hawaii DOH Clean Water Branch API for active advisories. When the state issues a brown water advisory, sewage spill notification, or beach advisory, it shows up on the relevant beach pages within minutes. We also track when advisories are cleared so you know when conditions are improving.
Every beach on the site has a bacteria risk rating from 1 (lowest risk) to 5 (highest risk). These ratings are based on Surfrider Foundation Blue Water Task Force testing data, Hawaii DOH Tier 1 monitoring history, and geographic factors like proximity to stream mouths, cesspools, and storm drains. These ratings help you understand a beach’s baseline risk even when no advisory is active.
You can sign up for free email alerts on any beach page. Choose your island, enter your email, and we’ll notify you when the DOH issues a new brown water advisory or sewage spill notification for your area. We check for new advisories every 6 hours and only send emails when there’s something new.
We never share your email with third parties. Unsubscribe any time with one click.
Hawaii has approximately 88,000 cesspools discharging an estimated 52 million gallons of undertreated sewage into the ground and coastal waters every day. The state only tests 57 of its 250+ beaches on a weekly basis. Surfrider Foundation testing found that 80% of Hawaii beaches tested exceeded health limits at least once.
The official DOH data exists, but it’s buried in a government database designed for regulators, not tourists. Most visitors have no idea this information is available, let alone how to find it or what it means.
Safe to Swim Hawaii was created to bridge that gap — to make water quality information accessible, understandable, and useful for anyone planning to swim in Hawaii.
Safe to Swim Hawaii is an independent passion project. We are not affiliated with the Hawaii Department of Health, any government agency, or any hotel or resort.
Our risk ratings are estimates based on publicly available data. They are not real-time laboratory measurements. Conditions can change rapidly, and no website can guarantee your safety in the ocean. “No DOH Alerts” means no advisory is currently posted — it does not mean the water was tested and found safe. DOH only monitors a fraction of Hawaii’s beaches, and some areas (like Moloka’i and Lāna’i) have no regular testing at all.
Always check the Hawaii DOH Clean Water Branch for official advisories before entering the water. When in doubt, don’t go out. 🤙
Questions, corrections, or feedback? Reach us at safetoswimhawaii@gmail.com.
Hawaii’s Department of Health monitors approximately 57 beaches statewide through regular bacteria testing. However, with over 300 swimmable beaches across the islands, many popular spots have no regular testing program. Water quality varies significantly based on rainfall, stream proximity, coastal development, and ocean circulation patterns.
After heavy rain, streams and storm drains carry bacteria, sewage, pesticides, and sediment into coastal waters. The DOH recommends staying out of the ocean for at least 48 to 72 hours after heavy rain, even if the water appears clear. Brown or murky water is a visible sign of contamination, but bacteria can be present in clear water near stream mouths.
This site aggregates data from six sources — DOH advisories, USGS stream monitoring (25 stations), NOAA tide and temperature data, NDBC wave buoys, NWS weather alerts, and City & County of Honolulu water testing — to provide a more complete picture than any single source.
The 72-hour rule is the standard guideline from the Hawaii Department of Health: avoid swimming for at least 72 hours after heavy rain stops, especially near stream mouths, canal outlets, and areas with brown or discolored water. This applies to all beaches across all islands.
Bacteria from urban runoff, agricultural land, and aging cesspool systems enters the ocean through streams and storm drains. Hawaii has approximately 88,000 cesspools — more than any other state — many of which leak untreated sewage into groundwater that eventually reaches the coast. Beaches near known cesspool contamination areas carry higher risk, particularly after rainfall.
⚠️ 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.
This site does not recommend or advise anyone to swim at any beach. We share government data and geographic analysis so you can make your own informed decisions. By using this site you accept full responsibility for your own safety. See our Terms of Use for full details.
When in doubt, don’t go out. 🤙