King Tides Flood Miami Streets on Clear Days from September to November

Roughly from September into November, the highest tides of the year push sea water up through the storm drain network in the lowest-lying parts of Miami-Dade. Streets flood on bright, cloudless days with no rain involved at all. Locals call them king tides. Tide charts call them perigean spring tides.

Where and when

The recurring locations are the low blocks of Miami Beach, parts of the Brickell and downtown waterfront, and low-lying stretches around Coconut Grove and the bayfront causeway approaches. Flooding peaks around the daily high tide and generally drains within an hour or two of it passing.

That predictability is the useful part. Unlike a storm, a king tide is on a published tide table weeks ahead.

What it means for a visitor

Mostly, wet feet. Water is usually ankle-deep and the disruption is short.

Cars are what actually get hurt. Brine standing around a wheel arch and under a floor pan corrodes things that are costly to put right, and no hire agreement anywhere treats that as ordinary use. In autumn, put the car in a garage instead of against a low kerb on the flagged days, and drive around standing salt water rather than through it.

Two smaller notes. Flood water that has come up through a drain is not clean, so treat it as you would any urban runoff rather than as sea water. And pumps run loudly in some Miami Beach neighbourhoods during these events, which surprises people staying at ground level.

Why it keeps coming up

Miami-Dade sits on porous limestone, which is why sea water arrives through the ground and the drains rather than over a sea wall. Both the county and the City of Miami Beach have spent heavily on pumps, raised roads and drainage over the past decade, and the works themselves are a visible feature of the autumn city.

Check the tide tables for your dates. It takes a minute and it decides where you park.