Mike wrote:
When: Sometimes as early as the last week in March, but more typically in April and May, concentrating on periods of steady or rising water temps. An especially good water temp range is 60 F - 68F, but the fish will certainly hit in cooler water than that. The problem is that they are not real common in near shore areas (for shore fly or lure anglers) until the temp hits around 60 F. The exceptions to this are in the few hundred yards below Fairmount Dam on the Schuylkill in Phila and at Trenton Falls, which is the tidal set of rapids between Morrisville, Pa and Trenton, NJ. At those two locations you can pretty much just go by the time of year and not necessarily the 60 F rule. That may also be true at some NJ creek mouths, but generally 60F is a good rule of thumb for near-shore areas. Good numbers are often present in the Schuylkill in April and May.

Where/when: Aside from what I mentioned above, once 60 F is hit and temps are steady or rising, fish near shore areas during the three hours before and three hours after high tide. Fish will typically be in 4-10 feet of water, but may be as shallow as 2 ft. So, if you wade out, they may be in front of you and behind you. Good spots on the Delaware Estuary are along sandy beaches with good current, creek mouths, island shorelines that face the main river channel, concrete rip-rapped areas, again paralleled by good current speed, sand bars, discharges from large wetlands, and, if you can stand it, sewage treatment plant discharges. Stay out of coves, other than at the points where the coves meet the main river. The greatest amount of shore access to good habitat in the Pa. portion of the Delaware Estuary is on the NJ side, if you can gain access. One good spot is the nature center at the end of the Tacony-Palmyra Bridge where there is good habitat for about a mile below the Tacony-Palmyra Bridge. That good habitat continues upstream to about a mile below Dredge Harbor, by-passing the walled stretch at Cinnaminson, NJ, but I am not aware of the legal access situation other than at the nature center. I see people shore fishing the stretch between TP bridge and Dredge Harbor at places, but I don't know the status of the lands they crossed to get to those places. Another potentially good spot is the shoreline along and upstream from National Park, NJ, where there is a public boat ramp. The fish sometimes show up on that sandy beach in big numbers.

On the Pa side, shore spots with good concentrations of fish are limited. One popular one is on the stone wall across the street and behind the UPS terminal, which is on the back side of the Phila Airport.