The Starting Lineup — 3 Flies You Must Have for the Month of August with CRO Guide Matt Weldon
- flyfish19
- Aug 4
- 4 min read
As the summer sun hangs high and the rivers of Colorado hit their seasonal stride, August can be one of the most productive—and visually stunning—months to fish. But success on the water requires more than just showing up. You need to be rigged right, reading conditions, and adjusting your tactics with the changing flows, hatches, and water temps.
We caught up with CRO Guide Matt Weldon, a seasoned local expert who spends almost every day on water throughout the summer. Matt shared his top three flies that every angler should have in their box this month. Whether you’re hiking into remote freestones or floating a big stretch of the Roaring Fork, this lineup will keep your rod bent and your net wet.
Let’s break down the August starting lineup, how to fish each fly, and why these patterns are catching fish all day long.
🥇1. Chubby Chernobyl — Purple, Size 10
The Dry Fly MVP of Late Summer
If there’s one fly that defines the late-summer terrestrial season in the Rockies, it’s the Chubby Chernobyl. Matt prefers the purple version in a size 10—and for good reason.
Why it works:
Hoppers and stoneflies are active.
Purple shows up well in mixed light conditions.
Big profile keeps it floating through riffles and pockets.
How to fish it:
Rig it as a single dry or as the top fly in a dry-dropper setup.
Pair with a Blow Torch or small nymph about 18–24 inches below.
Focus on riffles, foam lines, and undercut banks where trout are waiting to ambush a big meal.
Time of day:
Late morning through early evening (10am–5pm). Terrestrial action picks up once the day warms and bugs start moving.
Matt’s tip: “Don’t overdo your mend—just let that Chubby drift naturally. A twitch here and there can seal the deal when a fish is following but hesitant.”
🥈2. Blow Torch — Size 18
A Versatile Euro Nymph with Some Flash
The Blow Torch is a dynamite fly in summer conditions, especially when trout are being picky. With its slim profile and flashy hotspot, it works equally well as a dropper or part of a euro nymphing rig.
Why it works:
Mimics a variety of small bugs: mayfly nymphs, midges, even caddis larvae.
Slim profile drops fast, gets in the zone quickly.
Tungsten bead helps in pocket water and deeper seams.
How to fish it:
As a dropper off a Chubby in a dry-dropper setup.
Or fish it on a tight-line nymph rig with a heavier anchor fly up front.
Target transition water—those soft edges below faster water where fish stage to feed.
Time of day:
All day, but particularly effective during late-morning hatches and cloudy afternoons when trout are keyed in on small bugs.
Matt’s tip: “Fish a lighter tippet (5x or 6x) with the Blow Torch to get the fly down quick. Also, keep the dropper short, 16 inches is the sweet spot”
🥉3. Patriot — Size 16
An All-American Attractor Dry That Gets Eaten
This one punches way above its weight class. The Patriot in size 16 is a flashy attractor dry that imitates everything and nothing—and that’s what makes it so deadly. Fish mistake it for PMDs, small caddis, and even spinners.
Why it works:
Contrasting colors (blue, red, white) trigger reaction strikes.
High visibility in glare or low light.
Floats well, even in faster currents.
How to fish it:
Fish it solo over rising fish all day.
In a double dry fly rig, pair it with another small dry.
Great for technical water or spooky fish—it lands delicately but gets noticed.
Time of day:
All day, this fly is a staple amongst the CRO guides. A true work horse, even if fish aren’t rising, this fly forces them up!
Matt’s tip: “This fly shines in flat water. Cast upstream while wading or angled downstream from a boat and give it zero drag. Even smart fish can’t help themselves.”
🧠 Keep an Eye on Water Temps — Reel It Up at 68°F
As much as we love August fishing, it comes with an important responsibility. Trout are cold-water species and begin to experience serious physiological stress when water temps hit 68°F or higher.
Here’s what to do:
Carry a stream thermometer and check temps often, especially in the afternoons.
Fish early! First light to about 1–2pm is prime time during heat waves.
If the water hits 68°, reel it up and give the fish a break.
Practice barbless hooks and keep fish in the water as much as possible during release.
Matt puts it plainly: “If you love these fish and this fishery, be a steward. There’s always another day, another hatch.”
🎣 Book a Trip with Matt Weldon or Any CRO Guide
There’s fly fishing—and then there’s Colorado fly fishing in August, when the rivers sparkle, the bugs are popping, and the fish are hunting.
The Colorado, Eagle and Roaring Fork offer some of the most diverse and rewarding water in the West. Whether you’re looking for technical dries, high-country creeks, or float trips through big foam lines, we’ve got the water and the guides to make it happen.
🎯 Book a trip with Matt Weldon—his experience, patience, and local knowledge are unmatched. From beginners to seasoned anglers, you’ll walk away with fish stories, photos, and a deeper appreciation for these rivers.
Or team up with any of our seasoned CRO guides. We’re here to put you on fish, teach you the craft, and protect the resource while doing it.
📞 Call 970-236-1937 to lock in your August adventure. The fish are waiting. Are you ready?
Tight lines and cool water,
—The CRO Team
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