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TREND REPORT

Hawaii Water Quality — August 25, 2026

Big Island share of days without any island-wide DOH advisory fell 100pp between 14-day windows

By Safe to Swim Hawaii Team · Published August 25, 2026
↓
BIG ISLAND
-100pp worsening (0% of days without an island advisory)
↓
MAUI
-64pp worsening (29% of days without an island advisory)
↑
OʻAHU
+14pp improving (14% of days without an island advisory)
→
KAUAʻI
Mostly advisory-affected, stable (0% of days without an island advisory)

The share of days with no DOH advisory anywhere on Big Island fell 100 percentage points (100% in the prior 14-day window vs. 0% in the latest 14-day window).

This is a posted-advisory history metric, not a direct bacteria test or swimming-safety finding. Check the Big Island leaderboard, the individual beach page, and live DOH status for current context.

Where the islands stand today

Big Island

worsening

Big Island is worsening over the last 14 days (-100pp vs. the prior two weeks). All 7 of our tracked beaches on the island recorded one or more advisory days in that 30-day history window. NOAA's 7-day forecast is dry, which should halt new advisory activity and let the existing advisories begin to clear. See the Big Island leaderboard for the beach-by-beach ranking.

Maui

worsening

Maui is worsening over the last 14 days (-64pp vs. the prior two weeks). All 6 of our tracked beaches on the island recorded one or more advisory days in that 30-day history window. NOAA's 7-day forecast is dry, which should halt new advisory activity and let the existing advisories begin to clear. See the Maui leaderboard for the beach-by-beach ranking.

Oʻahu

improving

Oʻahu is improving over the last 14 days (+14pp vs. the prior two weeks). 12 of our 12 tracked beaches on the island recorded one or more advisory days in that 30-day history window. NOAA's 7-day forecast is dry, so the improving trend should continue. See the Oʻahu leaderboard for the beach-by-beach ranking.

Kauaʻi

mostly advisory-affected

Kauaʻi has remained mostly advisory-affected across both 14-day island-wide advisory-day windows (0% of days had no DOH advisory anywhere on the island in the latest window). All 6 of our tracked beaches on the island recorded one or more advisory days in that 30-day history window. NOAA's 7-day forecast is mild — scattered showers possible but unlikely to drive new advisories. See the Kauaʻi leaderboard for the beach-by-beach ranking.

Advisory-free leaders today (last 30 days)
Anini Beach
26/30 days advisory-free
Advisory-free →
Brennecke Beach
26/30 days advisory-free
Advisory-free →
Hanalei Bay
26/30 days advisory-free
Advisory-free →
Most advisory-affected tracked beaches (last 30 days)
Haleiwa Beach Park
2/30 days advisory-free
28 advisory days →
Hanakaʻoʻo Beach Park
17/30 days advisory-free
13 advisory days →
Sunset Beach
19/30 days advisory-free
11 advisory days →
NOAA 7-day forecast, per island tourist coast
  • Kohala Coast, Big Island: dry (max 12% chance of rain across next 7 days)
  • South Maui (Wailea / Kihei): dry (max 6% chance of rain across next 7 days)
  • South Shore O’ahu (Honolulu / Waikiki): dry (max 19% chance of rain across next 7 days)
  • Po’ipu, Kaua’i: mild (max 24% chance of rain across next 7 days)

For the always-live per-island outlook, see our Hawaii Water Quality Forecast, which regenerates daily from NOAA + DOH data.

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Live data and deeper context
Hawai’i Water Quality Data Hub — every resource in one place
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Hawaii Water Quality Forecast — 14-day trend + 7-day NOAA outlook
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Is Hawaii’s Beach Water Getting Cleaner or Dirtier? — YoY DOH data
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Cleanest Hawaii Beaches Right Now — statewide ranking
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Hawaii Citizen Water Testing — 100+ Surfrider BWTF sites
Coverage →
Why Hawaii Water Turns Brown After Rain — stream-mouth data
Data →
Hawaii Sewage Spills Today — live DOH tracker
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Where to Swim During a Brown Water Advisory
Guide →
Brown Water Advisory — live all islands + 72-hour rule
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Previous report — April 23, 2026
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Methodology: The island trend uses Hawaii DOH island-wide advisory-day history where available: a day counts as advisory-free only when no DOH advisory was recorded anywhere on that island. If island history is unavailable, the generator labels its tracked-beach-fraction fallback explicitly. The separate beach list summarizes 31 tracked beach histories. Forecast data comes from NOAA National Weather Service (api.weather.gov) at each island's primary tourist coast. This report is not a swim recommendation; always check the individual beach page and current local conditions before entering the water.