Oahu: Heavy Rain & Flood Risk—Beach Safety Alerts

Oahu’s beaches remain under water-quality advisories due to lingering contamination from recent storms. The state’s Clean Water Branch reports active sewage-spill and bacteria advisories, particularly on the south and windward shores. Avoid discolored or murky water—even if it looks clear, bacteria levels may be elevated. Surf is moderate (3–4 ft) across most shores, but heavy rain could worsen runoff and create unsafe conditions. Lifeguards are on duty at major beaches, but always heed posted warnings.

Heavy rain is expected to intensify Wednesday through Friday, with the heaviest downpours likely Thursday. A flood watch is in effect for all islands, with Oahu forecasted to receive 4–10 inches of rain. Temperatures will hover in the low 70s, with east winds at 5–10 mph. The storm system could linger into next week, bringing additional rounds of rain. Pack waterproof layers and plan for indoor alternatives if visiting.

Oahu is under a flood watch through Friday as a new storm system brings heavy rain and flash-flood risks. The National Weather Service warns that saturated soils from recent storms increase runoff concerns. No beach closures have been reported yet, but officials urge caution near water due to lingering contamination advisories. The city has activated its emergency operations center and positioned high-water vehicles across the island. Sandbag distribution is underway in flood-prone areas like Hauula.