Susquehanna & Allegheny bass shift into summer patterns as temps climb

What's Biting

What's Next

With the Susquehanna holding at 78°F and 5,140 cfs, the next two to three days will likely maintain summer-bass conditions across both the Susquehanna and Allegheny drainages. Mid-June water temperatures at this level tend to hold or tick slightly higher without significant rain — expect warm water to persist through the weekend unless a meaningful cold front moves through.

The new moon phase is your primary timing asset right now. Bass and other warmwater species typically shift into shallower feeding lies during low-light windows around a new moon, then pull back to deeper structure as the sun climbs. Plan your first casts at or before first light and extend through mid-morning, then return in the final hour before dark. Midday activity will likely concentrate in deeper pools, channel edges, and shaded structure along undercut banks.

Wired 2 Fish's summer bass breakdown captures the seasonal dynamic precisely: fish shallow early on surface and topwater presentations, then follow bass offshore to structure as the day heats up. For the Susquehanna's rocky current lines, swing-head jigs and crankbaits are particularly well-suited for summer smallmouth. Tactical Bassin's June bass coverage names the wobble-head jig paired with a shaky head worm as a confidence setup that "early Summer bass can resist," and their crankbait guide notes that shallow-to-mid-depth cranks trigger strikes when fish are parked on current breaks and transitional rock.

Catfish anglers should find conditions improving through the weekend. Water at 78°F sits near prime territory for channel and flathead cats. Target deep tail-outs, undercut banks, and log-laden eddies after dark on cut bait or live shad rigs positioned in the slower current seams adjacent to moving water.

One important caution: PA Sea Grant's June advisory on harmful algal blooms is a live concern at these temperatures. HABs can develop rapidly in warm, slow-moving backwaters and coves. If you encounter surface discoloration, foam with a paint-like or musty odor, or blue-green scum along shorelines, leave the area and keep pets and children out of the water. PA Sea Grant's free public webinar on June 25 is worth bookmarking for anyone spending regular time on Pennsylvania waters this summer.

Context

Mid-June on the Susquehanna and Allegheny historically marks the transition from spring-run species into full summer patterns. Water temperatures in the upper 70s by this date are not unusual for Pennsylvania's major river systems — the lower Susquehanna in particular tends to warm quickly once June settles in — but 78°F places the gauge at the upper edge of what smallmouth bass prefer (optimal range roughly 65–75°F) and decisively above the stress threshold for most trout.

Field & Stream's trout temperature guide notes that once water consistently exceeds 67–68°F, trout begin experiencing meaningful metabolic stress, and at 75°F and above, mortality risk from catch-and-release rises sharply. By mid-June in a typical Pennsylvania year, trout fishing on larger, unshaded river mainstems is already winding down, with action migrating to cold-water tributaries and higher-elevation streams that retain cooler temperatures longer into summer. Anglers should check for any hoot-owl advisories or mandatory catch-and-release orders on designated trout waters before heading out — qualifying language here is intentional, as these restrictions vary by water and season.

For bass, mid-June is historically a strong window on both rivers. Post-spawn smallmouth recover quickly and begin feeding aggressively as water climbs into the mid-to-upper 70s. Seasonal expectations place smallmouth in prime condition right now, actively chasing baitfish along current seams and rocky bottom structure. Walleye intel from Pennsylvania-specific sources was not available in this cycle, but the species is typically active through early summer on both systems before retreating to deeper, cooler water as temperatures peak.

Direct comparative angler-season reporting from Pennsylvania sources is limited this week — the PA Fish & Boat Biologist Reports feed did not return individual fisheries updates this cycle, and regional tackle-shop commentary on PA inland rivers was absent from available sources. The environmental data available (78°F, 5,140 cfs) is broadly consistent with a typical early-summer profile for this stretch of the Susquehanna, suggesting conditions are tracking on schedule rather than running unusually early or late.