July weather, stream flows, and summary
Long days and prolific hatches sum up fly fishing the Madison River in July. As the salmonfly hatch dwindles—some big bugs can still be found in early July—large insects give way to smaller, yet more abundant hatches of smaller insects such as Pale Morning Duns and various species of caddis. With consistent weather, fish- and angler-friendly stream flows, July is the pinnacle of summertime, easy-living fly fishing on the Madison River.
During July on the Madison River there are less than six days with measurable precipitation and average high temperatures in the 80s. The average length of daylight in July is around 15 hours per day. With the mild weather of July and plenty of daylight, opportunities to fish abound. From early morning mayfly hatches to fishing till dark during an evening caddis hatch, fly fishing the Madison in July is as diverse as it is unique.
Because snowmelt runoff is complete by July, the entire river usually flows clear and consistent. The Lower Madison—the river downstream of Ennis Lake and Ennis Lake Dam—is often the least desirable section. Ennis Lake is a shallow lake and during the long, sunny days of July the water temperature in the lake rises and is higher than the ideal range for actively feeding trout. Because of the high water temperatures on the lower river, the river upstream of Ennis is the main destination for fly fishing the Madison River in July.
A few salmonflies may still hatch in early July and hatches of Golden stoneflies and Yellow Sally stoneflies last well into the first few weeks. Stonefly nymphs are always prevalent in the Madison River, but as the calendar moves deeper into July PMDs and caddis dominate the hatches.
If May and June on the Madison are best described as varied because the experience from one day to the next runs the gamut, fly fishing the Madison in July is described as stable and consistent. Weather, stream flows, and hatches are dependable and pleasant, like a loyal Labrador Retriever.
July fishing: what to expect
The Madison River in July is an angler’s dream stream. There are opportunities for catching lots of fish, opportunities for catching big fish, and both can be done on the surface fishing dry flies, subsurface with tandem nymph rigs, or prospecting with large streamers.
A typical July day fly fishing the Madison River begins with choosing the method of choice. For anglers fond of fishing big dry flies, the first and last weeks of July are the favorites. Salmonflies and Golden stoneflies can still linger on the banks and at the end of the month grasshoppers begin to land in the water.
Hatches of PMDs can be strong throughout July and various caddis species hatch as well. Anglers less concerned about watching a trout rise to a dry fly and desire a fish on the line more than the process of how a fish gets on the line, will find plenty of opportunities to fish two-fly weighted nymph rigs. If a trophy trout is the desired result, slowly stripping or swinging a favorite streamer pattern is a good tactic. This is best done early or late in the day as the Madison River’s largest trout tend to shy away from feeding during the brightest hours of the day.
Because the days are long, an understanding of choosing the best time to fish is important. The lowlight hours of early morning and evening are often best for targeting large fish with streamers or dry flies. Later in the month when grasshoppers begin to show up in streamside grasses, midday and late afternoon are ideal for prospecting with a terrestrial.
PMD hatches typically begin mid-morning and can last up to five hours. Dry fly anglers can find some surface action even in the bright sun of midday and afternoon. During July, PMD, caddis, and stonefly nymphs are usually active around the clock, but for fishing nymphs for PMDs the best hours for nymphing are often the morning hours as the hatch is beginning and then during the hatch itself. Because Madison River caddis hatches are so varied, caddis nymphs can be active at any time during the day.
Even if the bulk of the salmonfly and Golden stonefly hatches are finished by early July, stonefly nymphs are a predominant insect species in the river and an available food source for hungry trout.
Where to find July trout on the Madison
Finding trout on the Madison River in July sounds easy, but it is actually a little more challenging than it sounds. As hatches of stoneflies wane, Madison River trout migrate away from bankside structure, spreading out in a wider array of habitats. Because the primary food source is no longer on the banks but hatching in various places throughout the river, to find trout in the Madison River in July the first step comes in understanding the habitat from which the various hatches are occurring.
Stoneflies tend to live on or near structure. Caddis live throughout the river. PMDs on the Madison River inhabit many places, but are most often found in riffles, shelfs, the heads of runs, and the tail outs of runs. These habitats all offer the primary needs for trout: available food source, cover from predators, cover from strong currents, and flowing water for oxygen. Because PMDs often live in the habitat trout desire, during the prolific PMD hatches on the Upper Madison in July, the trout tend to be hungry and happy and in the right spots.
Trout on the Madison River in July often move from the bank to holding and feeding lies away from the bank or in the middle of the river. Because of this migration, anglers fly fishing the Madison River in July must consider targeting water away from the bank and fishing less obvious habitats. Trout will follow the hatching insects, but a common mistake many Madison River anglers make during July is fishing habitats where the fish used to be, while not considering what is hatching at the exact moment and targeting that type of habitat.
Important July hatches
The Upper Madison River from Ennis Lake upstream to outside of West Yellowstone in July is an insect factory, pumping out strong hatch after strong hatch. Early in the month a few salmonflies and Golden stoneflies may still hatch, but the primary focus will be PMDs, caddis, a few Yellow Sally stoneflies, and towards the end of the of the month, terrestrials—grasshoppers, ants, and beetles.
PMD hatches typically begin mid-morning and last for several hours. Insects range in sizes from 12 to 18, with most being size 16. As a mayfly, it is important to understand trout may feed on emerging PMDs and not exclusively on fully hatched adults.
Grasshoppers, although not an aquatic insect, can be found on bankside grasses in late July. Opportunistic trout will eat a grasshopper that has mistakenly found its way onto the water.
Madison River fly box for July
PMD nymphs sizes 12 to 18
PMD emergers sizes 12 to 18
PMD dry flies sizes 12 to 16
Stonefly nymphs in brown and black in sizes 4 to 10
Golden stonefly dry flies in sizes 8 and 10
Salmonfly dries in size 6 and 8
Yellow Sally nymphs in sizes 10 to 16
Yellow Sally dry flies in sizes 10 to 16
Caddis pupae sizes 14 to 16
Caddis CDC emergers sizes 14 to 16
Caddis dry flies with dark grey, black or brown bodies in sizes 14 and 16;
Grasshoppers in sizes 6 to 12
Ants and beetles in sizes 12 to 18
Crayfish patterns in sizes 2 to 8
Sculpin patterns in sizes 2 to 6
Streamers in olive, black or brown in sizes 2 to 6