Recorded advisory history: Big Island was mostly advisory-affected in both 14-day windows; Maui had a higher advisory-free metric in the recent 14 days; O'ahu was mostly advisory-affected in both 14-day windows; Kaua'i was mostly advisory-affected in both 14-day windows.
Compare the last 14 days of recorded Hawaii DOH advisory history with the prior 14 days. The separate NOAA forecast describes rain chances at one coastal point per island; it does not predict future DOH advisories or beach water quality.
Mostly advisory-affected · no DOH advisory was recorded anywhere on Big Island on 0/14 recent days (0.0pp vs the prior window, when 0/14 days had none).
At least one DOH advisory was active somewhere on Big Island on 14 of the last 14 days. This island-wide event-day measure is not a test result for every beach.
Improving · no DOH advisory was recorded anywhere on Maui on 8/14 recent days (+28.6pp vs the prior window, when 4/14 days had none).
At least one DOH advisory was active somewhere on Maui on 6 of the last 14 days. This island-wide event-day measure is not a test result for every beach.
Mostly advisory-affected · no DOH advisory was recorded anywhere on O'ahu on 0/14 recent days (0.0pp vs the prior window, when 0/14 days had none).
At least one DOH advisory was active somewhere on O'ahu on 14 of the last 14 days. This island-wide event-day measure is not a test result for every beach.
Mostly advisory-affected · no DOH advisory was recorded anywhere on Kaua'i on 0/14 recent days (0.0pp vs the prior window, when 0/14 days had none).
At least one DOH advisory was active somewhere on Kaua'i on 14 of the last 14 days. This island-wide event-day measure is not a test result for every beach.
As of DOH + NOAA data through 2026-09-14, Recorded advisory history: Big Island was mostly advisory-affected in both 14-day windows; Maui had a higher advisory-free metric in the recent 14 days; O'ahu was mostly advisory-affected in both 14-day windows; Kaua'i was mostly advisory-affected in both 14-day windows. This page compares island-wide Hawaii Department of Health advisory-day history for the last 14 days against the 14 days before. If that island-wide history is unavailable, the page falls back to the advisory-free fraction among our tracked beaches and labels that metric explicitly. NOAA National Weather Service rainfall forecasts for the next 7 days appear separately. Neither source establishes current water quality at a beach.
Seven days is too noisy — single storms dominate and testing schedules can create false trends. Thirty days captures pre-trip-window data that's less relevant to a planner deciding right now. Fourteen days is long enough for signal, short enough to be responsive to current storms, and gives us two comparable windows (last 14 vs prior 14) to measure actual direction of change.
The NOAA forecast describes the chance of rain at one coastal point per island. Dry, mild and wet are categories based on those probabilities, not rainfall amounts or beach-water test results. The forecast is shown alongside past advisory history for planning context. It does not predict whether or when DOH will issue or lift an advisory, and a dry forecast does not establish that water is safe. Check current official DOH notices and local conditions before entering the water.
The trend data comes from the Hawaii Department of Health Clean Water Branch public API, which our pipeline polls daily. The preferred metric marks whether any DOH advisory was active anywhere on each island for each day; it does not claim every beach was tested. The weather forecast comes from NOAA's National Weather Service API (api.weather.gov) sampled at one leeward-coast point per island where trip planners actually go: Kohala Coast, South Maui, Honolulu South Shore, and Po'ipu. Both refresh daily.
No. This page compares recorded advisory history and shows rainfall forecasts. Advisory history does not measure bacteria levels at every beach, and rainfall probabilities do not establish current water quality or predict advisory clearance. Physical hazards (shore break, rip currents, surf, marine life) also vary by beach. Always check the individual beach page for current DOH status and local hazard information before entering the water.