When to Fly Fish in Colorado

What’s the Best Time of Year to Fish in Colorado

The thousands of miles of rivers and streams in Colorado offer wonderful opportunities to land fish all year round. I’ve fished Colorado waters every single season of the year and have had success.

It doesn’t matter if I was fishing during a snowstorm or on a warm summer day, the fish were willing to eat as long as I was able to mix up the techniques I used. With some trial and error, you’ll put fish in your net regardless of when you’re fly fishing in Colorado.

While all seasons can be productive in Colorado, spring continues to be the best time of year to land fish. Colorado winters can be harsh, and fish are subjected to cold water temperatures and less food. Once the weather warms and the runoff subsides, the fish enter a ferocious feeding phase and are most accessible. They haven’t seen hundreds of flies and aren’t overly picky.

Don’t let the higher productivity of the spring get you discouraged about the rest of the seasons! Take a look at the information about the rest of the seasons to learn some useful techniques.

Winter- Fishing Solitude

The winter in Colorado is a bit bi-polar. One day, it’ll be 15 degrees and snowing and the next it’ll be 60 degrees and sunny. This entirely has to do with the Rocky Mountains that stretch through the center of the state. As a result, winter fishing can also be temperamental! If the fish are in the midst of experiencing massive air temperature changes, their normal habits have to adapt.

Winter Brown Trout caught on a midge nymph
Winter Brown Trout caught on a midge nymph

Thankfully, however, you’ll likely have your portion of the water to yourself during these times. You’ll get chances to test out different techniques and work on some skills you may want to develop in your arsenal. Most anglers don’t bother trying to figure out winter fly fishing in Colorado because they understand the challenges that come with the fluctuating temperatures.

If you do want to fish in the winter, a mild winter day is usually your best bet. Somewhere in the 20s or 30s with slight cloud cover is likely to produce the most fish. This is what the weather is for most of the winter, so fish are willing to be more active during these times.

As always, you don’t have to be at the water at sunrise in the winter. Head out mid-morning when temperatures have warmed and the fish become more active.

Also, make sure you fish slower water! Fish are looking to conserve energy. They don’t want to have to fight the current for small amounts of food.

Winter Fly Fishing Setups

In the winter, you mainly hear guides encouraging anglers to use smaller flies and smaller tippet! This is the case in Colorado as well.

Rod Setup

Bring your 4 or 5-weight 9’ rod with a matching reel. Also, make sure your fly line is a floating line that matches the weight of your rod. You don’t need any extreme setups for winter fly fishing in Colorado. A medium-weight rod is good enough to do the trick.

Leader and Tippet

If you’re fishing dries and nymphs, a 3x or 4x leader with 4x or 5x tippet is plenty small for these fish. They’re not overly aggressive, so they take their time to look at their food before they eat it. If you’re fishing streamers, you can use 2x leader.

Ventures Fly Co 40 fly assortment - a perfect gift for dad
Here’s an Amazon shortcut link 👉 Ventures Fly Co Assortment

Ventures Fly Co. 40 Fly Assortment Has a Great Selection of Flies

This assortment has most of the flies needed lay the foundation for an effective fly box. the most common dries, nymphs and streamers. Check out the on water video review on YouTube – HERE


In the winter, nymphs are going to be your most productive. Things like Pheasant Tail and Prince Nymphs are going to land fish. Don’t shy away from small midge nymphs as well.

If you see hatches, they’re likely midges. A Parachute Adams is a solid dry fly option.

If you’re the first one to a slow-moving part of the water, don’t hesitate to toss a small streamer. A Woolly Bugger dead drifted through a hole can easily produce a fish.

Recommended Colorado Winter River

Fish the Arkansas River in the winter. It flows out of the Pueblo Reservoir in Pueblo, so temperatures are fairly regulated. This water is a bit warmer than other tailwaters you find, so that makes fishing productive. You can use dries here in the winter and land fish! Again, bring the Parachute Adams!

Spring- Go After Trophies

Once spring hits, it’s time to fish hard. By late May or early June, runoff should be subsided and the fish are ready to eat. Every fly angler knows what can happen as soon as that water starts to clear and levels drop! The potential for a trophy fish is high.

There are going to be some long days on the water, but it’s worth it. You’ve been cooped up in the house all winter long waiting for these days to happen.

Brown Trout Fly Fishing
Brown Trout Fly Fishing

Spring weather in Colorado is fairly mild. You’ll likely find temperatures somewhere in the 40’s to 50’s with the sun shining regularly. If you do happen to catch a rainstorm, don’t shy away from fishing. Rain can wash food into the water and fish are ready to eat. Yes, you’ll likely be a bit chilly, but the opportunities to land fish make up for it.

Also, in Colorado, fish like the rainbow and cutthroat trout begin to spawn in the spring. They need to feed heavily to prepare for the spawn, so if you find a body of water with a nice population of these fish, you’ll get continuous action while they’re aggressively feeding.

Make sure you’re careful when they begin their spawn! The fish are on “Redds” meaning they are laying eggs and shouldn’t be disturbed. Flows are going to be a bit higher than the ideal 200 CFS on most rivers, but it’s still manageable. Check the USGS website for up-to-date information on the river you’re hoping to fish in the spring.

Starting in March, the Colorado Fish and Wildlife Service begins stocking local rivers and ponds fairly heavily with 10-inch trout!

Orvis Clearwater 5 wt 9 foot Combo
Orvis Clearwater 5 wt-9 foot Combo

The Perfect Fly Rod Combo for Colorado

Orvis originated in the fly fishing business. The Orvis Clearwater Combo is perfectly balanced and comes with everything except flies. It’s so easy to cobble together an outfit that just doesn’t cast right. No worries with that using the Clearwater Fly Rod Combo.

Spring Fly Fishing Setups

Since the water is a bit cloudier and the fish are more eager to eat, you don’t have to be as inconspicuous when you’re fly fishing in the spring.

Rod & Reel

Most streams and rivers are going to be able to be fished with somewhere between a 4-weight and 6-weight rod. The larger rivers like the South Platte are going to require a 6-weight. Make sure your reel matches your rod.

Line, Leader, Tippet

Once spring hits, make sure you use a line that matches up well with your reel. Some anglers begin using one weight heavier line in the spring than their rod requires, but that’s more of a personal preference.

For the leader, make sure you’re using 0x or 1x for streamers and 3x or 4x leader for nymphs and dries. The fish are still going to get spooked, so use 4x or 5x leader for your dries and nymphs!


Pheasant Tail Nymph
Prince Nymph

Options are more plentiful for flies in the spring. Size 18-22 midges are still going to be extremely productive. Pheasant tails and Prince Nymphs are the best in the spring.

For dries, you can start throwing the Adams other midge representations! The occasional stonefly pattern would work as well.

Streamers are great through pools and slack water. The Woolly Buggers and Clouser Minnows are both great options.

Recommended River for Colorado in Spring

Check out the Gunnison River in the spring. It’s a little further south, so its temperatures warm quicker than other rivers. The river is fairly accessible and information is usually up to date on it! You won’t have to make the drive praying that it’s fishable. A call to a local fly shop is going to tell you. Thankfully, it’s usually productive during the spring besides the few weeks of runoff.

More Colorado Hot Spots to Toss a Fly

Summer- Bust Out the Dries

Come summer, the temperatures are warm and the fish are a bit more predictable. Nothing beats a summer evening in the Rocky Mountains throwing some dry flies at rising fish. Some of the best memories of my life are from these nights. From mid-June all the way through September, anglers have great chances at catching fish.

During the summer, however, it’s important to get out on the water during the most productive times of the day. The fish are going to be most active around sunrise and sunset. The middle of the day can be tough to fish! Usually, the temperatures are warm and the fish are deep waiting for the sun to begin setting.

Inclement weather is possible during the summer, especially if you’re fishing in the mountains. Wait for that afternoon storm to pass and the hatch to start. This is when fishing can become amazing!

Pay close attention to the temperatures as you’re fishing in the summer. In the summer, they average around 75 degrees.

Average Temperature in Colorado for Fishing
Average Temperature in Colorado for Fishing – data compiled from National Weather Service

Summer Fly Fishing Setups

Summer fly fishing in Colorado is extremely productive! However, if your equipment isn’t up for the challenge, you’re in trouble.

Rods & Reels

If you’re going to fly fish in Colorado in the summer, you’ll generally be okay with a 8’6” or 9’ 5 or 6-weight fly rod. If you’re fishing on smaller streams and mountain rivers, a 3-weight or 4-weight 8’ rod is fine. These are great for tight conditions and smaller water.

Match your reel to your fly rod for summer fly fishing in Colorado. You want to make sure you have a balanced setup, so your casting can be most accurate.

Line, Leader, Tippet

You’re likely going to only need floating line when you’re summer fishing in Colorado, but if you’re fishing deep water on a hot day, a sink tip is a good option.

For streamers, use 0x or 1x leader. For your nymphs and dries, a 3x or 4x leader with 4x or 5x tippet is a good option. The water is clear and the fish can spook!


Dry flies are the most fun to use in the summer. Caddis, Stoneflies and Midge patterns are all available. So are terrestrials. The Chubby Chernobyl and any sort of ant pattern can work well. Also, the Golden Stonefly can be killer!

Stonefly nymphs and flies like the Prince Nymph are great.

For streamers, the Sculpin Leech, Sex Dungeon, Clouser Minnow and Woolly Bugger are all going to work.

Recommended Colorado Summer River

It’s hard to argue with the South Platte River for summer Colorado fly fishing. You have over a dozen access points to choose from when making your travel plans. The water temperature stays solid throughout the summer! Check out the Dream Stream section below the Spinney Reservoir.

Fall- Always Underrated

Fly fishing in the fall in Colorado is extremely underrated. Life slows down after a busy summer, and the rivers are nowhere near as busy as they were in June and July. A trip to the river in late September and October is a treat. The temperatures are still warm enough and the fish are looking to fatten up before the cold of the winter arrives.

As the water temperatures cool, the fish become more active throughout the day. The water is also lower and clearer, so you’re going to have to be especially on your game to make sure your presentations and drifts are accurate.

Brown Trout with a small midge from the Colorado River
Brown Trout with a small midge from the Colorado River

Brown trout also spawn in the fall, so you’re going to have a nice amount of action from these fish pre and post-spawn!

If possible, find a day that has some cool and cloudy weather. The hatches are going to be continuous and the fish are far more active. Those calm and sunny days are frustratingly challenging!

Fall Fly Fishing Setups

You don’t have to go crazy with your fall fly fishing setups for Colorado. Similar setups to what you have over the summer should work.

Rods and Reels

Your 5-weight 9’ rod is great for most Colorado rivers. In the fall, the fish aren’t going to give you a fight like they do immediately after runoff in the spring. They’re still aggressive, but not as ferocious as you might find. For smaller water, use a 3-weight or 4-weight 8’ rod. For bigger water, use a 9’ 6-weight.

Match your reel to whatever rod you choose! Balance is key.

Line, Leader and Tippet

You’re going to be okay with using floating line during the fall. Due to the falling water temperatures and lower water, you likely won’t be fishing anywhere that’s overly deep.

For your leader, use 1x or 2x for streamers and 3x or 4x for nymphs and dries. When it comes to tippet, you’re going to have to go small. The fish have seen flies all summer and the water is clear. Use 4x or 5x!


In the fall, use BWO patterns. Traditional BWO dry patterns are great. You can also use Parachute Adams, Sparkle RS-2s and Juju Baetis flies.

BWO Blue Winged Olive for Fly Fishing
BWO Blue Winged Olive for Fly Fishing

For your nymphs, stick with the Pheasant Tail!

Streamers are usually very productive in the fall. Large streamers size 1 or 2 are going to catch fish. The Autumn Splendor, Sex Dungeon, Clouser Minnow, Wolly Bugger and Home Invader are all great streamer options.

Recommended River for Fall in Colorado

The Lower Eagle River near the towns of Eagle and Gypsum is a great fall river. It’s fairly easy to access and the fish are especially eager to eat. Bring those large streamers to use in the pools and float your dries as soon as you start seeing hatches.

Last Cast for Colorado

While the spring is almost always going to be the most productive time of year for Colorado fly fishing, it’s hard to beat the fish you can catch in the fall. Combine this with less pressure and you’re in for a treat. Thankfully, Colorado fly fishing can be productive all year long! Stay patient and you’ll land fish.

Are you looking for some great How To Fly Fish Articles? Checkout this list:

Danny Mooers is a high school English teacher in Arizona with a love for fly fishing. Growing up in Minnesota gave him the opportunity to experience all types of fishing and grow his skills. After living out in the Western United States for several summers in college, his fly fishing obsession grew. Having the opportunity to share in his passion for fishing through writing is a dream come true. It’s a lifelong hobby and he strives to make it understandable for people of all skill levels

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