Oahu Flooding Worsens as Kona Low Brings Repeated Rounds of Heavy Rain

Flooding across Oahu reaches a two-decade high

Oahu is facing its most severe flooding in more than 20 years as repeated rounds of heavy rain continue to soak already waterlogged ground. Officials say the situation remains dynamic, with emergency crews still conducting search-and-rescue operations and residents in some areas under urgent evacuation orders.

More than 230 people have been rescued so far, according to the latest updates. At the same time, about 5,500 people remain under evacuation orders, driven in part by rising water levels and growing concern about the Wahiawa dam. The ongoing rainfall has compounded runoff issues from earlier storms, escalating flood worries even as rain at times slows.

Damage estimates climb, assessment still incomplete

Officials have warned that the full scope of destruction is not yet known. Dozens—if not hundreds—of homes were damaged, but the extent of the impacts has been difficult to assess amid ongoing flooding and active response efforts. Honolulu Mayor Rick Blangiardi said officials have not been able to fully evaluate the destruction.

Even with those limitations, damage estimates have already reached $1 billion and are continuing to rise. Reported impacts include damage to homes, roads, schools, airports, and a hospital on Maui. With additional rain expected in the coming days, officials are preparing for the possibility that impacts could expand or worsen.

Wahiawa dam monitored near critical levels

A central concern in the emergency response is the 120-year-old Wahiawa dam, which officials say is near critical levels and at risk of failing. Rising water levels have contributed to evacuation orders affecting thousands of residents.

Authorities have issued stark warnings for nearby communities, telling residents to leave immediately because the dam “may collapse or breach at any time.” The warning also advises residents to carpool due to heavy traffic on the island, underscoring how evacuation logistics can become challenging during fast-moving flood emergencies.

North Shore inundation prompts urgent evacuation orders

Some of the most serious impacts have been concentrated north of Honolulu, where heavy rain has inundated communities and catastrophic flash flooding has been reported on Oahu. Emergency sirens sounded along the island’s North Shore as rising waters damaged homes and conditions deteriorated.

Honolulu officials issued a “LEAVE NOW” evacuation order at 5:35 a.m. Friday for Waialua and Haleiwa, citing “Extremely dangerous flooding and Wahiawa Dam is high.” The North Shore of Oahu has been under flash flood warnings since early Friday morning, highlighting the persistence and intensity of the threat.

Rescues continue, including airlifts from a youth camp

Emergency response has included both ground and air operations. The National Guard and the Honolulu Fire Department airlifted 72 children and adults who had been attending a spring break youth camp in affected areas. The airlift reflects the difficult conditions responders have faced as floodwaters cut off routes and made travel hazardous.

Search-and-rescue operations are ongoing, and officials continue to monitor conditions as water levels change. The combination of repeated rainfall and runoff from earlier storms has kept the response in an extended posture rather than a short, isolated emergency.

Health impacts reported amid prolonged wet conditions

Beyond property damage and evacuations, flooding conditions have also brought health risks. At least 10 people have been hospitalized for hypothermia. Prolonged exposure to cool, wet conditions can become dangerous quickly, especially during evacuations or when people are stranded by rising water.

Officials have not detailed the circumstances of the hospitalizations, but the reports underscore that major flooding events can create medical emergencies even outside the immediate dangers of swift water.

What’s driving the rain: a Kona low and repeated moisture surges

This round of flooding rain has been attributed to a Kona low located north of Hawaii. Kona lows are low-pressure systems known for reversing winds across the Hawaiian Islands, bringing heavy rainfall and gusty winds to communities that do not typically experience such conditions.

In this case, the concern is not limited to a single storm. Officials and meteorologists have emphasized that repeated rounds of rain—combined with runoff from last week’s heavy rainfall—have caused totals to add up rapidly. With limited breaks between systems, the ground’s ability to absorb additional water diminishes, increasing the likelihood of flash flooding and sustained high water levels.

A series of low-pressure systems has continued to draw tropical Pacific moisture and push it over the islands. The cumulative effect, after very heavy rainfall from the first Kona low last weekend and additional smaller systems, has contributed to the escalating flood situation.

Rain totals and near-term forecast

Parts of Oahu have recorded 8 to 12 inches of rain, with several more inches expected over the weekend. The additional rainfall is a key factor in the ongoing risk outlook, particularly for low-lying areas and locations downstream from swelling waterways.

Even if rainfall rates ease at times, runoff can continue to raise water levels, especially where drainage is overwhelmed or where earlier rainfall has saturated soils. Officials have expressed particular concern that the Wahiawa dam could be overtopped, a scenario that would intensify downstream risks.

How the broader weather pattern is being described

Meteorologist Jonathan Belles described the flooding as being connected in some ways to a broader pattern affecting the United States. He noted that when one region experiences heat, another often sees cooler, wetter weather. In his explanation, the West has been seeing heat while the East has been slightly stormier, and that pattern extends farther west as well.

According to Belles, cooler, wetter weather has persisted over Hawaii and into Alaska. He added that until a major storm system shifts the pattern or the pattern slowly breaks down, both flooding and heat could persist. While the immediate emergency is centered on Oahu’s flooding, the commentary points to a longer-lived setup that may not resolve quickly.

State response: National Guard activated, flood watch remains

The Hawaii National Guard has been activated in response to the flooding. Gov. Josh Green described the storm as “very severe right now,” particularly on the northern part of Oahu, and said it was going to be a “very touch-and-go-day.”

Most of the state remains under a flood watch, reflecting the potential for additional flooding beyond the hardest-hit areas. With multiple islands reporting impacts—including damage to a Maui hospital—officials are treating the event as a statewide concern even as Oahu remains at the center of the most urgent warnings.

Key points at a glance

• Flooding on Oahu is described as the worst in more than 20 years.
• More than 230 people have been rescued; search-and-rescue operations continue.
• About 5,500 people are under evacuation orders, partly due to concerns at the Wahiawa dam.
• Damage estimates have reached $1 billion and are rising; assessments are still incomplete.
• Parts of Oahu have seen 8–12 inches of rain, with more expected over the weekend.
• The 120-year-old Wahiawa dam is near critical levels; residents have been warned it may collapse or breach.
• At least 10 people have been hospitalized for hypothermia.
• The Hawaii National Guard has been activated; most of the state remains under a flood watch.

What to watch next

With several more inches of rain expected in the near term, the immediate focus remains on flood-prone communities and on the status of the Wahiawa dam. Officials have warned that conditions can change quickly, especially where runoff continues to build after repeated rainfall.

For residents and travelers across the islands, the continuing flood watch signals that the risk is not confined to a single neighborhood or a single day. The situation remains driven by a persistent weather pattern, and the impacts—rescues, evacuations, infrastructure damage, and health risks—are expected to remain central concerns as the rain continues.