Late Winter Fly Fishing: The Season Of Change

March 7, 2026

This time of year in New Hampshire is always interesting. It’s the point in the season when Mother Nature can’t quite decide if she wants to stay in winter or start transitioning into spring. One day temperatures creep up into the upper 30s, low 40s, or even 50s. Then the next day we are right back to freezing.

Slowly but surely though, things start to change.

Ice shelves begin to shrink, snowbanks soften, and little by little the rivers start opening up. Some of the smaller streams and tributaries are usually the first to break free, while bigger rivers can still have plenty of ice hanging around in the slower sections.

Even though it might still look like the middle of winter, trout are already beginning to respond to these seasonal changes.

One of the big events just around the corner is the rainbow trout spawn. As we move through late winter and toward early spring, rainbow trout begin pushing into tributaries and shallow gravel areas to spawn. Normally this will take place from April to late May, but depending on the winter we get, I've seen some rainbows spawn in March if it’s been a mild winter. Lake run rainbows in particular will often stage near tributary mouths before moving upstream once water conditions line up.

This is something I always keep an eye on this time of year. Tributaries connected to lakes can go from looking completely quiet to suddenly holding fish once they open up and flows stabilize. A stretch of water that didn’t have much going on a week ago can turn on pretty quickly.

Of course, when the spawn starts happening it’s important to be mindful of where you’re fishing. I always recommend avoiding fish that are actively spawning on redds and instead targeting fish that are staging nearby or feeding in deeper runs and tailouts.

Late winter fishing is usually all about slowing things down. For example, you’ll want to target the slowest, deepest pools on the river or stream as fish will be looking trying to stay as warm as they can until water temps reach more comfortable temperatures. Trout species like water temps ranging from 35 to 65 degrees. Anything below 35 they become extremely dormant to try and survive the cold, and anything over 70 degrees they can become lethargic, stressed and which in these higher temperatures can quickly become lethal for the trout.

Cold water means trout don’t want to move very far to eat, so presentations need to be accurate and natural. I spend a lot of time focusing on deeper pools, slower seams, and any structure that allows trout to conserve energy out of the heavier current.

Another thing I pay close attention to is water temperature. Even a one or two degree increase can make a noticeable difference in fish activity. Many days this time of year the fishing actually improves in the afternoon once the sun has had a chance to warm the water slightly.

When it comes to flies, trout are usually feeding below the surface this time of year since insect activity is still pretty limited.

One of my go to choices is midge patterns in sizes 24–18. Midges are one of the few insects that are consistently present in cold water, and trout feed on them year-round. Small, simple midge patterns can be incredibly effective during the late winter months.

Another fly I like to fish this time of year is the Woolly Bugger. Natural colors like black, olive/green, white, and brown in sizes 10–6 tend to work really well. These flies do a great job imitating a variety of food sources like small baitfish, leeches, and other aquatic life. Most of the time I like to fish them dead drifted through deeper runs, almost like a nymph, but they can also be very effective when slowly stripped through pools or slower water. In cold water especially, a slower presentation usually gets better results.

Egg patterns can also be very productive as we get closer to the rainbow trout spawn. Eggs naturally drift downstream during spawning activity, and trout are always looking for that easy meal. Fishing egg patterns through deeper runs or tailouts below spawning areas can often produce solid fish.

Another simple, but effective option is worm patterns. These include San Juan worms, Squirmy Worms, and Mop Flies. Keep the length of these worm patterns between half an inch to 2 inches in length (winter bugs are small). With snowmelt, rain events, and fluctuating water levels, worms frequently get washed into rivers this time of year. Trout recognize them as an easy, high protein meal and will pick them up without hesitation. Dead drifting worm patterns through slower seams and deeper pools can be extremely effective when fish aren’t responding to other flies.

One of the things I really enjoy about fishing this time of year is how quiet the rivers are. It’s very rare I cross paths with other anglers this time of year. Most anglers don’t want to fish in the cold, which I don’t blame them for. However, if you’re willing to dress warm and put in the time, you can have some really rewarding days on the water.

Before long, spring will be fully here. Snowmelt will bump up river flows, water temps will slowly start to increase, insect hatches will start becoming more consistent, and trout will spread out into more typical feeding water.

But right now, during this transition period, anglers who pay attention to river conditions and fish behavior can find themselves in the right place at the right time.

Sometimes all it takes is an open stretch of river, a good drift, and a little patience.