1953. But that was wind, not rain.
Northerly gale force winds held back the high tide in the North Sea so that the level didn't drop. The next high tide charged down the North Sea with the wind behind it leading to a double height tide.
Kings Lynn was badly flooded, large parts of the Netherlands were under water, as was Canvey Island. We lived in Grays and stayed dry but both Purfleet and Tilbury, 3 miles west and east respectively were both badly flooded.
Other places would have suffered too but I was only 8 at the time and that is all I can remember!