U.S. River Conditions, July to September 2023

This is an animation showing the changing conditions relative to the historic record of USGS streamgages from July 1, 2023 to September 30, 2023. The river conditions shown range from the driest condition seen at a gage (red open circles) to the wettest (blue closed circles). A purple outer ring around a gage indicates it is flooding.   

At the beginning of July, parts of Alaska received twice the normal rainfall while flooding occurred in New England. Concurrently, much of the Heartland and parts of the Northwest experienced drought conditions until the end of September.  

August saw drought conditions expanding in the South while flooding occurred in Southern California from remnant Hurricane Hilary. Hurricane Idalia brought flooding to parts of the Southeast as August ended.  

The beginning of September saw high flows in parts of the West. As September ended, an atmospheric river alleviated low flows in the Pacific Northwest. Additionally, Tropical Storm Ophelia brought flooding to parts of the Eastern U.S., where flooding also occurred in and around New York City.  

Note that both USGS gage height and National Weather Service flood stage are necessary to determine flooding conditions. The combination was available for 80% of streamgages at the time this graphic was produced. Only publicly available data from Water Data for the Nation were used.