Shortly before 5 a.m. HST Sunday, Daniel K. Inouye International Airport (PHNL) was reporting mostly clear skies and a cool 63°F. That calm start will not last. Scattered rain showers are expected to return through the day, with a warm afternoon high near 79°F and the chance for brief, heavy bursts over windward neighborhoods.
Showers Today, Heavier Rain Tonight Into Monday
Scattered showers are forecast through Sunday, with daytime chances around 30 to 40 percent and most spots picking up under a quarter inch in quick moving cells. Later tonight into Monday, energy dropping in from the north is expected to ramp things up, raising the odds for moderate to locally heavy rainfall, especially over windward-facing slopes where higher totals are possible.
According to the National Weather Service Honolulu, soils are still saturated in some areas, so a statewide Flood Watch may be needed later today if trends continue.
Timing And Where
The wettest bands will favor windward slopes and higher terrain, while interior and leeward neighborhoods see more hit-or-miss, sea breeze driven showers. During the heavier pulses, ponding and localized street flooding could crop up in low-lying urban areas, which can slow commutes where drainage is already marginal. For more on how this unsettled pattern set up over the weekend, see our Honolulu soaked coverage.
Surf And Wind Impacts
A long-period north-northeast swell is expected to build starting Monday afternoon, with exposed north and east shores potentially reaching advisory levels. Low-end warning conditions are possible Monday night into Tuesday, along with overwash and harbor surges at more vulnerable spots.
Trade winds will make a comeback and turn breezy into early next week, with northeast winds commonly in the mid teens and gusts into the low 20s in exposed locations. The forecast and marine discussion come from the National Weather Service Honolulu, which also notes that a High Wind Warning and a Winter Weather Advisory remain in effect for Big Island summits.
How To Prepare
If you live in windward or low-lying neighborhoods, it is a good time to move vehicles off streets that are known to flood, avoid driving through standing water, and secure loose outdoor items ahead of the breezier trades. You can sign up for Oʻahu emergency texts and targeted alerts through HNL Alert or follow local county channels for road closure and shelter updates.
We will update this space if a Flood Watch or other warnings are issued. Until then, plan on spotty disruptions to commutes and outdoor plans Monday as showers increase and surf builds along north and east shores.
