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TREND REPORT

Hawaii Water Quality — April 25, 2026

Kauaʻi water quality is worsening (-64pp in 14 days)

BIG ISLAND
Steady (100% clean)
MAUI
+33pp improving
OʻAHU
-20pp worsening
KAUAʻI
-64pp worsening

Kauaʻi ocean water quality worsened 64 percentage points over the last 14 days (64% clean two weeks ago vs. 0% clean 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

stable

Big Island is stable — no significant change in the last 14 days. 0 of our 7 tracked beaches on the island have active advisory days in the last 30 days. NOAA's 7-day forecast is dry, so the current pattern should hold. See the Big Island leaderboard for the beach-by-beach ranking.

Maui

improving

Maui is improving over the last 14 days (+33pp vs. the prior two weeks). 6 of our 6 tracked beaches on the island have active advisory days in the last 30 days. NOAA's 7-day forecast is dry, so the current pattern should hold. See the Maui leaderboard for the beach-by-beach ranking.

Oʻahu

worsening

Oʻahu is worsening over the last 14 days (-20pp vs. the prior two weeks). 12 of our 12 tracked beaches on the island have active advisory days in the last 30 days. 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

worsening

Kauaʻi is worsening over the last 14 days (-64pp vs. the prior two weeks). 6 of our 6 tracked beaches on the island have active advisory days in the last 30 days. 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 9% chance of rain across next 7 days)
  • South Maui (Wailea / Kihei): dry (max 8% chance of rain across next 7 days)
  • South Shore O’ahu (Honolulu / Waikiki): mild (max 25% chance of rain across next 7 days)
  • Po’ipu, Kaua’i: mild (max 32% 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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Methodology: Statistics in this report come from our pipelineʻs aggregation of Hawaii DOH Clean Water Branch advisory data across 31 tracked beaches (last 14 days compared against the 14 days before). Forecast data from NOAA National Weather Service (api.weather.gov) sampled at each islandʻs primary tourist coast. All numbers accurate as of publication. This report describes water-quality trends and forecast; it is not a swim recommendation. Physical hazards (shore break, rip currents, surf, marine life) are independent of water quality. Always check the individual beach page and local conditions before entering the water.