Susquehanna summer bite: catfish spawn peaks and smallmouth go offshore
USGS gauge 01540500 logged 76°F and 5,510 cfs on the Susquehanna the evening of June 16, putting the river firmly in early-summer mode. Water temps in the mid-70s mark prime catfish spawn timing. Wired 2 Fish notes that during the spawn, big catfish abandon the bottom and move into the shallows, requiring a shift from the usual deep-hole presentation to flats and bank edges. For smallmouth, the post-spawn transition is underway. On The Water's recent post-spawn bass coverage highlights finesse presentations as the play when fish are recovering and resettling on summer structure. Tactical Bassin's early-summer bass content points to swing-head jigs and crankbaits as confidence producers right now, especially along deeper channel edges. The new moon phase on June 17 typically compresses feeding windows toward low-light periods; dusk and pre-dawn sessions should be most productive. PA Sea Grant has flagged a June 25 webinar on harmful algal blooms, a warm-water hazard worth monitoring on slower Susquehanna backwaters.
Current Conditions
- Water temp
- 76°F
- Moon
- New Moon
- Tide / flow
- Susquehanna at 5,510 cfs per USGS gauge 01540500; moderate summer flow with good access for small boats and most tributary wading.
- Weather
- Check local forecast before heading out.
New to these readings? What do water temp, cfs, tide, and moon phase actually mean for fishing?
What's Biting
Catfish (Channel & Flathead)
shallow structure in 2-6 feet: undercut banks, boulder piles, and woody debris
Smallmouth Bass
finesse rigs and swing-head jigs along channel edges and gravel transitions
Walleye
deep outside bends and dam tailwaters in 12-20 feet
What's Next
The Susquehanna is holding at moderate summer flow with 5,510 cfs at gauge 01540500 and a water temperature of 76°F. If the next several days bring continued warm, sunny weather, temperatures could nudge toward the upper 70s. That is still within the productive bite range, but pay attention to shallower, slower sections of both the Susquehanna and Allegheny, where warm stagnant water can suppress dissolved oxygen and push fish deeper.
Catfish are in or near peak spawn right now. Per Wired 2 Fish, this is the window when big flatheads and channel cats that normally hold in deep holes are accessible in shallow water near structure: undercut banks, boulder piles, and woody debris in 2 to 6 feet. Once water temps continue rising and spawn activity wraps up over the next several weeks, expect the fish to vacate the shallows and resume their typical deep-hole, bottom-feeding pattern. Fish this shallow window while it lasts.
Smalmouth bass are transitioning out of the spawn. On The Water's post-spawn bass coverage recommends finesse presentations: ned rigs, drop-shots, and compact swimbaits for fish that are actively feeding but not yet committed to hard-charging summer behavior. By the weekend, if temperatures hold or rise, look for smallmouth to start pushing into summer feeding positions along current seams, deeper gravel transitions, and submerged boulder faces. Tactical Bassin recommends swing-head jigs and wobble-head combos for early-summer bass in deeper structure, noting these produce quality fish rather than just numbers.
The new moon on June 17 means minimal moonlight at night, which historically concentrates feeding activity at dusk, dawn, and through the dark hours. Plan first-light sessions for the best topwater shots at smallmouth, and evening catfish sessions along productive bank edges.
Walleye on both systems typically settle into 12 to 20 feet of water by mid-June, holding near outside bends, dam tailwaters, and submerged ledges. No current cycle intel specifically covers Allegheny or Susquehanna walleye, but standard summer practice applies. Check PA Fish & Boat Biologist Reports for any stocking notes or structure observations on specific river sections you plan to target.
Harmful algal blooms are a developing watch item per PA Sea Grant. Their June 25 webinar will cover identification and avoidance. As summer temperatures climb, any backwater section, slough, or reservoir connected to either system is a candidate for HAB development. Avoid areas with visible surface scum, foam, or blue-green coloring, and keep pets and children away from any affected water.
Context
Mid-June is the reliable inflection point in Pennsylvania's river fishing calendar. By the third week of June, water temperatures in the Susquehanna and Allegheny drainage have typically crossed 70°F, completing the spring-to-summer flip: trout action has largely moved to cold tributary headwaters and tailwater sections, while warmwater species take center stage. A reading of 76°F at gauge 01540500 is consistent with what anglers typically encounter at this point in the season, neither notably high nor low for the date.
Flow at 5,510 cfs indicates moderate conditions. The Susquehanna responds quickly to precipitation events upstream, and summer flows on the main stem can range from under 2,000 cfs in drought years to well over 20,000 cfs after sustained rain. A mid-range reading like this allows access by small boat and canoe throughout much of the main stem, and wading in most tributary runs. That is a normal mid-June baseline absent recent heavy rain.
The catfish spawn at this water temperature is a seasonal feature that most anglers overlook. Fishing the Midwest notes that rivers consistently deliver outstanding action through the summer months, particularly on larger systems, and the mid-June catfish shallow-water window fits squarely within that observation. The Susquehanna is known for large populations of both channel and flathead catfish; mid-June represents one of the few periods when trophy-class flatheads are reliably findable in water accessible to shore anglers and wade fishermen.
No direct PA-specific angler reports, tackle shop intel, or charter data were available in this reporting cycle to benchmark conditions against prior years. The PA Fish & Boat Commission Biologist Reports page provides stream-by-stream updates from district fisheries biologists and is the most reliable first-look source for Susquehanna and Allegheny drainage conditions. Checking that directly will fill the local-knowledge gap this report cannot address from the current data set.
This report is synthesized by Hooked Fisherman from real-time NOAA buoy data, USGS stream gauges, and current reports across regional fishing blogs, captain updates, and angler forums. Source names are cited inline where they appear. Check local regulations before keeping fish. Never trust a single source for a trip decision.