Do Trout Stop Eating During Winter?

Winter is probably my favorite time of year to fly fish. It’s quiet, the summer crowds are gone, and there’s a very good chance at hooking into nice trout. I didn’t always have this love affair with fishing in snowy weather, though. It took a few years—and plenty of frozen fingers—before I started looking forward to ice in my guides.

Most anglers I meet have one of two viewpoints on winter fishing: they either love it as well, or they assume the fish quit eating and essentially hibernate until spring. That second perspective is far often the most common, and it’s what I assumed as well before I learned more about how a trout’s metabolism works, and how to use that to my advantage during winter.

Trout Metabolism 101

During spring, summer, and early fall, fish are actively feeding. They’re consistently on the lookout for their next meal, whether that’s a blue-winged olive mayfly, a crawdad, or a leech.

This is largely a reaction to the rest of the food chain. Most aquatic insects are active during the warmest parts of the year. With the most food available during a relatively short window, trout take advantage by feeding consistently, and sometimes aggressively.

As the cold season rolls around, though, aquatic insects shut down. The caddis, stoneflies, and mayflies that were such a large part of a trout’s diet quit moving around. Riffles are no longer the food factory of the river.

Trout respond by moving out of the fastest water—where they expend a lot of energy—and into the slowest, deepest parts of the river. Their metabolism slows down significantly, and they won’t spend much energy chasing down food.

They’re not hibernating, but since trout are cold-blooded, their metabolic rate is impacted by the water temperatures. When temperatures drop, a trout’s metabolism slows down, and they act lethargically.

So What?

Alright, trout slow down in the winter (don’t we all?). Why does that matter? They’re not hibernating, so they’ll still eat, right?

Well, it matters because this change in behavior forces you to adapt both your fly selection and how you rig up for a day on the water.

Winter Flies

Midges are the only aquatic insect that completes a full life cycle during the winter (midges will hatch into adults year-round). They’re always a part of a trout’s diet, but in winter, they form an even larger portion of what trout eat.

Mayflies, caddis, and stoneflies aren’t completely off the menu. Yes, they’re not moving around much during winter. However, they’ll still get dislodged from rocks and underwater branches and drift through the current. Free-swimming mayfly nymphs will still move around and look for food, so they might find themselves in a trout’s stomach.

Most of your focus, though, should be on midges, and then your other critters that are active year-round. Scuds, sow bugs, and worms are an important part of a trout’s diet during winter, as are eggs.

Winter Rigs

Unless you get into a midge hatch, fish usually won’t be high in the water column in winter. They seek out the deepest, slowest parts of the river to spend winter. There’s still food for them to eat, but they have to spend significantly less energy than they do when holding in riffles and runs.

Your winter rigs should focus on quickly getting flies deep, and staying there. Smaller flies are the name of the game in many places, though a larger (12-14) point fly works well to drop flies into the strike zone, and helps you retain sensitivity in your rig. If you can, avoid adding split shot, as that makes the rig clunky to cast and less sensitive to the soft bites that are a hallmark of winter fishing.

Wrapping Up

A trout’s metabolism slows down in winter, which means trout aren’t feeding as aggressively. While you can find midges hatching—and fish eating those dry flies—in winter, that’s the exception rather than the rule. Most often, you’ll need to fish smaller nymphs, through deep water, to get fish to eat.

Focus on achieving the best drift possible, and pay attention to the slightest pause or change in direction from your indicator. Trout eat with tiny bites this time of year, so if you’re waiting to see a bobber shoot underwater, you might wait a while.

Above all, go out and experience winter fishing. It’s not for everyone, but there’s something wonderfully relaxing about spending so much time out in the quiet and cold.