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TREND REPORT

Hawaii Water Quality — May 25, 2026

Maui water quality is worsening (-50pp in 14 days)

BIG ISLAND
Mostly advisory-affected, stable (0% of days with no DOH advisory anywhere)
MAUI
-50pp worsening
OʻAHU
Mostly advisory-affected, stable (0% of days with no DOH advisory anywhere)
KAUAʻI
+21pp improving

Maui ocean water quality worsened 50 percentage points over the last 14 days (100% advisory-free two weeks ago vs. 50% advisory-free now).

For a trip in the next week, prioritize islands with stronger structural protection (dry coasts, reef enclosure, no major streams). See cleanest Hawaiian island and BWA alternatives.

Where the islands stand today

Big Island

mostly advisory-affected, stable

Big Island has been mostly advisory-affected across both 14-day island-wide advisory-day windows. Our 7 tracked beaches happen not to overlap with the DOH advisories driving this signal — the worsening trend is from island-wide or other-area advisory events. 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 (-50pp vs. the prior two weeks). 1 of our 6 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

mostly advisory-affected, stable

Oʻahu has been mostly advisory-affected across both 14-day island-wide advisory-day windows. 2 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 mild — scattered showers possible but unlikely to drive new advisories. See the Oʻahu leaderboard for the beach-by-beach ranking.

Kauaʻi

improving

Kauaʻi is improving over the last 14 days (+21pp vs. the prior two weeks). 6 of our 6 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.

NOAA 7-day forecast, per island tourist coast
  • Kohala Coast, Big Island: dry (max 6% chance of rain across next 7 days)
  • South Maui (Wailea / Kihei): dry (max 7% chance of rain across next 7 days)
  • South Shore O’ahu (Honolulu / Waikiki): mild (max 30% 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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New report every day: trend per island, NOAA forecast, 30-day advisory-free leaders and most advisory-affected tracked beaches. Free — unsubscribe anytime.

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.