Napa River - Fagan Slough Entrance UV IndexUnited StatesCANapa CountyNapa River - Fagan Slough Entrance1-Day3-Day Graph Plots Open in Graphs UV Forecast NOAANapa River - Fagan Slough Entrance UV forecast issued yesterday at 10:05 pm. Next forecast at approx. 10:05 pm.Get WillyWeather+ to remove ads