When is the Best Time of Year to Fly Fish in Montana? (Plan Your Trip)

I have been fly fishing for many years. It still amazes me how many people ask me pretty much the same questions where ever I fly fish. When are the best times to fly fish in Montana.

The best and easiest way to answer this is, whenever you can get there.

The reason that I say this is because there is no right or wrong answer to the question. Montana has all of the different seasons and offers many different types of fly fishing.

There are lots of options for fishing some of this nation’s beautiful and best blue ribbon rivers and streams. Here I will try to outline Montana’s flyfishing seasons.

This might give you an idea of what you can expect during the different time periods. I am going to start with the end of the year because that is what is upon us.

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mountain river in Montana

Winter (November – March)

You can and will want to fish year-round in Montana. You want to look for is a day that is not too windy and has air temperatures above 32 degrees. Then you will want to concentrate on the warmest part of the day if you can. Like times such as 10 am – 2 pm, when the trout are most active this time of year.

The pressure is usually light on the rivers and streams. Midges are usually the most common insects hatching. Even though the trout have slowed down their activity you can still have a great day fishing slowly and thoroughly. Nymph fishing is usually the best technique for you to find success.

Try being in nature in the quiet of the winter months you will find it can be very relaxing. Most of the major rivers stay open year-round. By fishing when the conditions permit, you can go find a lot of water all by yourself and have a great day.

Fall (September – October)

This is one of my personal favorite time periods to fish. After Labor Day, many families have kids back in school and the pressure on all the rivers tend to relax. Fishing with terrestrials is still a good possibility.

We experience another stonefly hatch that has some completely different qualities that our early season hatch didn’t have. These nocturnal stones hatch at night and throwing big attractors can bring explosive strikes on the surface.

Dropping a small stonefly nymph off the dry can also be very productive. As the month of October approaches, another hatch of the Blue Winged Olives emerges. These are smaller than their springtime cousins, these trout will key into this hatch. Many of the western rivers and fishing the small technical dries will test the most experienced anglers.

As the brown trout began to stage up to spawn, the streamer fishing can be very rewarding as well. Fishing 6-7 weight rods and throwing big streamers for trophy brown trout is a lot of work but can get you that fish of a lifetime. When you see a huge brown trout come off the bank. Then charge your fly, and try ripping the rod out of your hand it is an unbelievable experience.

Peak Season (July – Early September)

This season is when we see the majority of people book their fishing trips. The weather is the most consistent, the fishing is good to great and it’s a great time to fish Montana.

From late June to early July we experience our famous Salmon fly hatch. These small clumsy flies are not only a delicacy for the trout but a major meal that they cannot get enough of.

This is a very busy time of the year and it is a difficult hatch to try and fish. This is because as the hatch progresses upstream it depends a lot on the air temperatures. But, that one day you do hit it just right it will be the best day of dry fly fishing in your life—guaranteed.

It can also be very busy on the river with many others looking for that same epic day. I feel that if you get an experienced guide has the tips and tricks to give you a great time.

In July and August, it is the terrestrial time in our area of the state. If you like throwing big attractor dries or foam flies that you can see, this is a great time.

You should try fishing hot summer days, blind casting big grasshopper patterns from either the bank or mid-river. These can help to bring up some big trophy trout on the Yellowstone or Madison Rivers. We also see other hatches such as golden stones, PMD’s, Tricos, and various Caddis flies.

Run-Off (Mid May – June)

Generally starting in the middle of May our snowpack begins to melt. Then many of the rivers and streams begin to swell and get dirty. During this time of the year because of the rivers’ clarity some days they are fishable and others not.

The time and length of the runoff are dictated by MotherNature. It depends on how long it lasts and on the snowpack depths and how fast it melts. On an average year, the runoff usually lasts around 4 to 6weeks, it depends on many factors.

We will usually have options to fish during this time period with areas that have fishable water. But we may not have all the options available during our run-off period. You want to remember that we do not need “crystal clear” water to have great fishing.

If you have high water it will generally push the trout toward the banks. With just two or three feet of visibility, the fishing can be very good. By fishing during the runoff season, it will allow you to use stronger leaders and bigger flies. This can also help to make sure that your success rate increases.

Try throwing 1x leaders and some big rubber legs patterns they are normal and can be very successful. You should also concentrate on many of the rivers that aren’t affected much by the runoff. Some of the rivers such as the Missouri and Beaverhead rivers don’t see the effects of the runoff.

These can offer a great option for fishing clear water with a chance for fishing dry flies. These rivers are very popular especially during this time of year and advance planning to arrange your lodging are recommended.

Spring Season (April – Mid May)

Starting around April and continuing through the middle of May, spring hits Southwestern Montana. Water temperatures will start to warm up and the trout and the insect life start to get more active.

The rainbow trout should begin to spawn and opportunities for dry fly fishing should increase. The fishing pressure is usually light during this time of the year. Finding the opportunities to have the rivers and streams almost to your self should be very good.

Many days you may find daytime temperatures in the mid-’50s to ’60s, but the occasional squall or rainy day is not uncommon. Sometime during May when the water temperatures reach the mid 50’s.

They experience an unbelievable hatch of caddis flies named the Mother’s day caddis hatch. Some rivers like the Yellowstone and Madison Rivers will experience a fantastic hatch where the caddis flies hatch out by the millions.

It is not uncommon to see fish rising from one bank to the other. Some mats of the spent caddis can be as big as a sheet of plywood. Trout will gorge themselves in the back eddies or behind protruding boulders. This time of the year is one of our favorite times to fish because of the lack of pressure and the trout are uneducated.


It does not really matter when you go fishing. And it does not matter what type of fishing you are going to do just go fishing and enjoy yourself.

It doesn’t matter if it’s fly fishing, spin fishing, or bait fishing just go enjoy Mother Nature. Take your friends or family fishing and enjoy the great outdoors.

Bob Hoffmann

The author of this post is Bob Hoffmann. Bob has spend most of his childhood fishing with his father and now share all his knowledge with other anglers. Feel free to leave a comment below.

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