State specific Data:

New Jersey:

NJ DEP places to fish
http://www.njfishandwildlife.com/fishplc.htm

Delaware River Water Temps
http://www.delawareriver.net/temp.php

Delaware River USGS celsius water temps and Scientific measurements (Streamflow data)
http://waterdata.usgs.gov/nj/nwis/uv?01463500