Flash Flood Warnings Issued for Oahu and Kauai

UPDATE: 6:25 a.m. HST, Saturday, February 21, 2026 – Flash flood warnings remain in effect for Oahu and Kauai as heavy rainfall continues to impact both islands. The National Weather Service (NWS) in Honolulu has extended the warning for Oahu until 9:45 p.m. HST and for Kauai until 9 a.m. HST.

Oahu Flash Flood Warning Extended

As of 6:19 a.m. HST, radar and automated rain gauges indicate heavy rain falling over the Koolau Mountains, with the heaviest rainfall occurring between Maunawili, and Hauula. Rainfall rates are currently between 2 to 3 inches per hour, leading to ongoing or expected flash flooding. The warning area includes Honolulu, Waipio, Waiahole, Waikane, Kahaluu, Ahuimanu, Pearl City, Aiea, Halawa, Mililani, Kaaawa, Moanalua, Salt Lake, Waikele, Wahiawa, Punaluu, Waipahu, Kalihi, Kaneohe and Wheeler Field.

Kauai Flash Flood Warning and Road Closures

Kauai remains under a flash flood warning until 9 a.m. HST. Radar indicates continued heavy rainfall across the island. The Hanalei River has reached levels high enough to prompt the Kauai Police Department to close Kuhio Highway near the Hanalei River Bridge due to significant water over the roadway. Flash flooding is currently ongoing.

Flood Watch for Niihau and Continued Threat

Both Oahu, Kauai, and Niihau are likewise under a flood watch through this afternoon. The NWS reports that an upper-level trough moving through the northwestern islands is producing periods of heavy showers and isolated thunderstorms. Forecasters expect the trough to move north later this afternoon, potentially diminishing the flooding threat.

Earlier Reports and Rainfall Rates

Earlier this morning, at 4:28 a.m. HST, radar and automated rain gauges showed heavy rain falling along a convergence band over the Koolau Mountains on Oahu, with rainfall rates of 2 to 4 inches per hour. Stream levels were already rising, and flash flooding was occurring. On Kauai, at 3:49 a.m. HST, radar indicated heavy rain over windward sections of the island, with rainfall rates of 2 to 3 inches per hour. The Princeville side of Kuhio Highway was previously closed near the Hanalei River Bridge due to water over the roadway.

Safety Precautions

The NWS advises the public to:

• Stay away from streams, rivers, drainage ditches, and culverts, even if they appear dry.
• Do not cross fast-flowing or rising water in a vehicle or on foot – turn around, don’t drown.
• Be especially cautious at night when it is harder to recognize the dangers of flooding.

Forecasters also warn that heavy rains may cause rock and mudslides in steep terrain areas.