King tides at Norfolk

What counts as a king tide

There is no official definition. NOAA does not publish one, and the California King Tides Project simply means the highest predicted tides of the year. This page lists every predicted high water of 7.0 ft or more above MLLW, which on this stretch of coast picks out the handful of days each winter when the water comes up unusually far.

They happen when the moon is closest to Earth and new or full at the same time, with the Earth near its own closest approach to the sun. That alignment stacks the solar and lunar pulls together, and it lands in November, December and January far more often than not.

These are predictions of astronomical tide only. A winter storm arriving on a king tide is what causes flooding, because surge and wind can add a foot or more on top of the figures here.

What a king tide means at Norfolk

Norfolk floods on these tides, and more often each decade — the land here is sinking as well as the sea rising, which is why this is among the fastest relative sea level rise on the American coast.

The Hague, Ghent and the low streets near the waterfront go under on the highest tides of the year without a storm. A northeast wind holding water in the bay makes it considerably worse.