Potomac River - Port Tobacco River Entrance UV IndexUnited StatesMDCharles CountyPotomac River - Port Tobacco River Entrance1-Day3-Day Graph Plots Open in Graphs UV Forecast NOAAPotomac River - Port Tobacco River Entrance UV forecast issued today at 1:05 am. Next forecast at approx. 1:05 am.Get WillyWeather+ to remove ads