“Sunny day flooding” is a term for flooding that occurs when no rain is falling. It could occur when rain falls upstream of an area and the streamflow from that rain overflows the banks of the stream. In this article, it is flooding that is occurring from rising sea levels along the coast of Florida just north of Miami. In Shorecrest, a community near the coast that is built on wetlands, they have gone from seeing flooding once or twice a year to almost every high tide. They are seeing drastic changes in their coastline, too, as inlets widen and move farther up into the community. You can read more at The Guardian here.

Source: National Park Service via Commons Wikimedia