Summer heat on PA rivers shifts the bite to smallmouth and catfish

What's Biting

What's Next

With water already at 79°F on June 13 and summer air temperatures expected to hold across central and western Pennsylvania, the main-stem Susquehanna and Allegheny will likely stay warm or tick slightly higher over the next two to three days. That has direct implications for when and where you fish.

Early morning is the prime window — roughly 5:30 to 8 a.m. — before surface temps climb and smallmouth push off the shallows. Rocky shoals and gravel bars that hold crayfish and shad will concentrate feeding bass at first light. Once the sun is high, Tactical Bassin's June bass breakdown is a reliable playbook: a wobble-head jig paired with a soft plastic swimbait is among their most-cited confidence plays for offshore fish that have moved to channel depth seeking cooler water. Wired 2 Fish's summer crankbait feature echoes the strategy — medium-diving crankbaits along ledge transitions and rocky channel edges cover water efficiently and trigger reaction strikes from bass that are no longer actively pursuing surface forage.

Catfish anglers should plan for evening and overnight sessions. As air temps drop after sunset, surface water cools a few degrees through riffled sections, and big channel cats move shallower to pursue shad in current seams. Cut shad and fresh cut bait are standard producers in the Susquehanna and Allegheny's deeper pool tail-outs.

PA Sea Grant's June 25 webinar on harmful algal blooms is worth keeping in mind as you scout water this weekend. Slow-moving backwater pools in the lower Susquehanna are the most susceptible to bloom development when temps are elevated. If you observe discolored, paint-like surface mats or an unusual odor near any impounded water, move to a moving-water section.

The waning crescent moon this weekend minimizes overnight light, a condition that generally compresses feeding windows but can make those windows very productive. Catfish and smallmouth often hit hard in short, intense bursts at dusk and dawn under dark-moon conditions — plan to be on your best structure right at the transition, not 30 minutes into it. Fishing the Midwest's summer river piece recommends working alternating deep and shallow structure along river corridors, a pattern that maps directly to the Susquehanna's pool-riffle-run sequence and the Allegheny's deep canyon bends.

Context

Water at 79°F on the Susquehanna main stem in mid-June is warm but not dramatically out of range for this stretch of river at this time of year. The Susquehanna's broad, shallow profile and relatively low gradient through central Pennsylvania means it heats faster than headwater tributaries — upper-70s readings at central PA gauges are historically common by mid-June in average or above-average years. This season appears to be arriving roughly on schedule, with no strong signal from the available sourced feeds that temperatures are unusually advanced or depressed compared to recent years.

No current on-the-water bite data from PA Fish & Boat's Biologist Reports was available in this week's sourced feeds, which limits direct comparison with prior-year conditions on these specific rivers. Historically, those reports flag mid-June as the period when main-stem Susquehanna smallmouth fully transition from post-spawn recovery into aggressive summer feeding patterns — a shift that aligns with the current water temperature reading and the approach of the summer solstice.

Field & Stream's trout temperature guide provides useful seasonal context: the mid-70s are consistently cited as the upper edge of the comfort zone for brown and rainbow trout in moving water. Once main-stem gauges push past that threshold — as the Susquehanna clearly has — access to cold-water species effectively shifts to spring-fed tributaries and higher-elevation freestone streams. This is a seasonal reality for PA's wild and stocked trout fisheries alike, and it is typical for mid-June rather than an anomaly.

The 5,770 cfs flow at gauge 01540500 represents moderate summer conditions on the Susquehanna. Historically, summer flows fluctuate considerably with precipitation, but this reading suggests the river is in accessible shape — neither drought-low, where fish concentrate uncomfortably in deep pools, nor flood-elevated, where current becomes difficult to fish. For anglers who haven't been out yet this season, conditions appear to be in a normal mid-June window: warming water, active warm-water species, and a clear imperative to fish early or late.