When you’re heading out on a salmon fishing charter from the scenic port of Saugatuck, Michigan, it’s more than just casting lines and hoping for a bite—it’s about understanding the seasonal rhythms of Lake Michigan’s prized sportfish: Chinook (King) and Coho salmon. These magnificent fish follow distinct migration and feeding patterns throughout the year, and knowing how they behave in relation to water temperature, baitfish movement, and weather shifts can make or break your catch. In this blog post, we’ll take you behind the scenes of what’s happening beneath the surface and show you how we use that knowledge to put fish in the box on every trip.

The Seasonal Journey of Salmon in Lake Michigan

Spring Awakening: The Ice Breaks and the Bite Begins

As winter releases its grip and the icy waters of Lake Michigan begin to warm, Chinook and Coho salmon emerge from deeper waters to feed. This is the pre-spawn feeding frenzy—a time of high energy and opportunity for anglers.

In early spring (April through early May), salmon are typically found in the warmer, shallower waters near shore, especially around river mouths where runoff creates nutrient-rich zones that attract baitfish like alewives and smelt. Coho salmon are usually the first to move in, often in large schools, feeding aggressively on the abundant forage. Chinook follow, slightly deeper but still accessible.

For charters running out of Saugatuck, this means tight-line trolling in close to shore with small spoons, crankbaits, and body baits. Surface water temperatures in the 40°F to 50°F range are key—anything warmer usually means the salmon are pushing farther offshore or deeper in the water column.

Summer Structure: Deep Waters and Thermoclines

By mid to late June, the lake has stratified. This means that a thermocline—a layer of rapidly changing water temperature—has formed, typically between 40 to 70 feet deep. Salmon, especially Chinook, love this stable zone because it offers ideal temperatures (around 50°F) and a consistent food supply.

This is when downriggers, divers, and copper lines lines become essential. Salmon will hold at specific depths depending on the location of the thermocline and the presence of baitfish. Alewife schools will often show up as dense clouds on the sonar, and where the bait goes, the salmon follow. Kings are particularly notorious for staying locked in on these deep bait balls, making precision trolling essential.

Off the port of Saugatuck, we target these fish with larger spoons, meat rigs, and flasher-fly combos in a deep spread. Downriggers are set from 60 to 100 feet, with divers working the mid-depths and copper lines or copper lines reaching into those less-pressured thermal zones.

Late Summer Frenzy: The Pre-Spawn Push

As August rolls into September, the action starts to heat up again—literally and figuratively. Chinook salmon begin their annual spawning migration, moving toward their natal rivers. Though the Kalamazoo River near Saugatuck isn’t a major spawning tributary for Kings, the area still sees heavy migratory traffic as the fish push south along the coast.

These fish are driven by instinct more than hunger at this point, but they’ll still strike out of aggression, territoriality, or habit. Their bodies start to change—they darken, their flesh softens, and they’re no longer the chrome-bright salmon of early summer. But they’re big, strong, and offer some of the most adrenaline-pumping action of the year.

Trolling speed slows during this period. Flashers and flies take center stage, and anglers might use glow-in-the-dark patterns or UV-enhanced baits to trigger strikes in lower light or murky water conditions. It’s not uncommon to find big Kings in 30 to 50 feet of water near shore, and early morning trips are especially productive.

Fall and Beyond: Coho Come Back and Kings Fade Out

While Chinook salmon are nearing the end of their lifecycle in the fall, Coho salmon take the spotlight. They run later and often stay in shallower water longer. By October, they’re congregating near river mouths and harbors, especially after heavy rains that raise river flows and cue the spawning run.

Coho are a blast to catch this time of year—acrobatic, aggressive, and still silver-bright. Their preferred water temperatures are slightly cooler than Chinook, and they’re more tolerant of shallower, changing environments. We often switch to smaller presentations and troll slower, keeping our spread tight to structure and current breaks near the Saugatuck shoreline.

Temperature: The Great Underwater Traffic Light

Temperature is one of the most powerful forces driving salmon behavior in Lake Michigan. Salmon are cold-water fish, and their ideal temperature range is generally between 45°F and 55°F. They’ll follow that comfort zone both horizontally and vertically through the lake.

In spring, warming surface temps draw bait and salmon shallow. In summer, they descend to the stable comfort of the thermocline. In fall, as surface temps cool, they rise again and push toward rivers. Our charter fishing success is directly tied to reading temperature trends—using onboard temp probes, sonar, and years of experience to dial in where the fish will be.

When water temperatures spike above 65°F near the surface in summer, we know to go deep. But if we get a cold-water upwelling or stormy conditions that mix the water column, the fish can move quickly. That’s why we constantly adjust our trolling spread based on what our electronics and lines are telling us.

Baitfish: Follow the Food, Find the Fish

Salmon don’t move at random. Their behavior is largely dictated by the movement of baitfish—primarily alewives, smelt, and shad in Lake Michigan. When large schools of baitfish stack up in a given area, salmon won’t be far behind.

In spring, baitfish cluster near river mouths and warmer water, drawing Coho and Chinook in shallow. During the summer, baitfish move offshore and deeper, often hovering around drop-offs, temperature breaks, and underwater structure. We look for “bait balls” on sonar and set our trolling gear just above them, as salmon typically attack from below.

In the fall, baitfish start thinning out or migrating themselves, and salmon shift to pre-spawn behavior. At this stage, even though food is less of a motivator, we still find that matching the hatch—using spoons and flies that mimic the current baitfish profile—produces more strikes.

What This Means for Your Charter Fishing Experience

So what should you expect when you climb aboard one of our Saugatuck salmon charters? Here’s a seasonal breakdown:

• Spring (April-May): Nearshore fishing with lighter tackle. Expect fast Coho action and occasional early Kings. Shorter runs, lots of bites, and plenty of excitement.
• Summer (June-August): Deeper trolling with a full spread of downriggers, copper lines, and divers. Targeting mature Chinook in open water. Long runs, deep fish, and big rewards.
• Late Summer (September): Kings on the move! Nearshore trolling for heavy, aggressive Chinook ready to spawn. Slower speeds, but explosive strikes.
• Fall (October): Coho mania near the piers and river mouths. Smaller gear, more finesse, but lots of action—especially for families and newer anglers.

The Big Picture: Fishing With Knowledge

At the heart of every successful salmon charter is a deep understanding of fish behavior. We don’t just troll aimlessly—we read the water, study the sonar, watch the weather, and use years of local experience to predict where the fish will be and what they’ll respond to.

By understanding the migration patterns, feeding behavior, and seasonal cues of Chinook and Coho salmon, we put you in the best possible position to have a memorable trip. Whether you’re a seasoned angler chasing a trophy King or a first-timer hoping to feel the thrill of a salmon on the line, our knowledge of salmon behavior is what makes it all come together.

So next time you step aboard with us in Saugatuck, know that there’s a science behind the action—and you’re fishing with a crew who knows exactly how to turn the lake’s seasonal cycles into your next great catch.

Ready to book your charter and chase some silver? Contact us today and let’s get out there—because the fish are always moving, and so are we.