Today and Wednesday will mark a return of so-called king tides to local shores, raising water levels about five inches above normal and possibly higher in December and January, according to climate scientists.

King tides are the highest predicted astronomical tides of a given year. Their localized impacts depend on wave conditions.

Many Hawaii residents were introduced to the phenomenon last summer during an unusually strong run of king tides that saw water levels peaking at more than 10 inches above anticipated levels, causing serious flooding in certain areas.

The largest king tides are expected to occur over the coming week, and again in the first weeks of December and January.

The University of Hawaii Sea Grant Center for Coastal and Climate Science and Resilience, the University of Hawaii Sea Level Center, and the Pacific Islands Ocean Observing System continue to monitor unusually high ocean water levels in the central Pacific.

Hawaii Sea Grant is sponsoring the Hawaii and Pacific Islands King Tides citizen science project and is again asking the community to help capture photos of local shorelines during king tides events. Over the summer more than 2,400 photographs were submitted by citizen scientists through the project’s free mobile application.

Since the winter king tides occur very early in the morning, the best dates to capture the highest high tides are before 8 a.m. today (high tide occurs at 6:39 a.m.), and Wednesday; and December 6 – 7 prior to 8:00 a.m. For more information, visit PacificIslandsKingTides.org.