Cooling water on Lake St. Clair: down 4°F to 52°F, turnover ahead

The numbers

The latest reading is 52°F, taken a few days ago. Each point on the chart is a clear-sky reading of the surface; cloudy days leave gaps, so the line connects the readings we have.

4°F in 12 days is the kind of drop that triggers turnover.

Lake St. Clair spreads over about 275,000 acres and roughly 130 miles of shoreline at full pool. At its deepest the lake reaches around 25 ft. Anglers come to Lake St. Clair for muskie, smallmouth bass and walleye. Shallow water gives up its heat fast, so a few cold, clear nights show up quickly at the surface.

Is the lake about to turn over?

All summer a deep lake sits in layers: warm, light water on top and cold, heavy water below, with little mixing between them. As the surface cools into the 50s it becomes as dense as the water underneath, sinks, and the whole lake mixes from top to bottom.

With the surface at 52°F, Lake St. Clair is close. During turnover fish scatter and the bite gets tough for a few days; afterwards the whole water column has fresh oxygen and fish can roam at any depth.

Shallow flats and the backs of creeks usually mix and clear first. If the main lake looks dirty, start there.

Who is biting at this temperature

The map shows how the surface temperature varies across the lake on the latest clear reading; warmer pockets tend to hold bait.

Muskie on Lake St. Clair are a solid pick. Cool water is big-fish season for pike and muskie; they fatten up along weed edges and breaks.

Smallmouth bass here are worth a try. Smallmouth handle cool water well; the 50s often bring some of the biggest fish of the year onto rocky points.

On the same water, walleye are in a good mood. Cool water is walleye weather: the bite is strong at dusk and after dark. Low light is best, on reefs and weed edges.

Yellow perch on Lake St. Clair are a strong bet. Perch school near weed edges and soft bottom as the water cools.

48°52°FSurface °F

Where to start

On Lake St. Clair, start at the upper arm marked on the map, fishing 10 to 14 ft. The lake narrows toward the incoming river or creek; moving water carries food. It suits walleye and yellow perch; jig and minnow or crankbait along the edge. The best window there is 3:30 pm to 5:00 pm. Down at that depth the water is about 49°F, against 50°F on top.

On a cooling lake, work the deeper end of that range early and move up as the sun warms the water.

DamDeepest water N 5 miles

5101520Depth, ft Free spot todayPlace to stay

See this spot in 3-D

Level check

The level reads 574.3 ft, 0.1 ft higher than a week ago and 0.4 ft down over 29 days. That puts it 0.9 ft below the usual level for this time of year. A steady level keeps fish on familiar spots, so what worked last week should still be close.

How to fish it this week

• Set your depth for 52°F water: The surface is 52°F (a few days ago). Work the middle of the range early, then follow the fish shallower as the sun warms the water.
• Tie on the right bait: At this spot, jig and minnow or crankbait along the edge. Muskie: big baits along weed edges and breaks.
• Work the edge, not the middle: Slow everything down: long pauses, light line, small baits. Most bites come as the bait sits still. Position the boat in deep water and cast up onto the shallow side, so your bait falls down the slope the way fish face.
• Use the wind, carefully: Saturday brings wind from the northwest with gusts near 13 mph: bait stacks up on the northwest side, and fish follow. A light chop is a good thing: it breaks up the light and makes fish bolder.

About Lake St. Clair

With about 275,000 acres and roughly 130 miles of shoreline at full pool, Lake St. Clair is a lot of water to cover. The deepest water sits around 25 ft. Anglers come to Lake St. Clair for muskie, smallmouth bass and walleye. Knowing which fish are comfortable at today's temperature narrows a big lake down to a few good spots.

Weather and bite outlook

Sunday has the gentlest weather: wind around 8 mph, partly sunny, topping out near 47°F.

Circle Saturday, Sunday and Monday on the calendar: 6 of the next 7 days rate good or better. On Friday the strongest window runs 3:30 pm to 5:00 pm, and on Saturday 3:45 pm to 5:45 pm.