September might just be my favorite month for trout fishing. The hot dog days of summer have passed, replaced by cool mornings and sunny days. The water temperatures slowly cool throughout the month allowing the trout to be active throughout the day.
Best of all, the summer vacations are over, and the mountain valleys are less crowded. It is a much better time to find solitude on a mountain stream.
These cooler water conditions also encourage trout to move out of their summer heat refuges and repopulate lower stretches of rivers.
This is also the time of year when brook and brown trout start to think about spawning. This is an exciting time for anglers because as the spawn approaches they typically become more aggressive.
At the same time, trout are trying to fatten up before the lean winter months, it is not uncommon for trout to feed strongly throughout the day.
What are rainbow trout doing in September?
In September, the brown and brook trout are getting ready to spawn, so they are busy heading towards the cooler water of the upper tributaries.
Rainbow trout, on the other hand, spawn in the spring. In September, rainbow trout are typically feeding hard, trying to pack on as much condition as possible.
Depending on how fast the water temperature drops, some rainbow trout might migrate from cold water streams where they spent the summer, to slower moving, slightly warmer water further downstream.
Later in the month, they might be found feeding downstream of brown trout redds, eating any eggs dislodged into the current.
Insect activity in September
Large hopper flies are the highlight of the summer trout fishing season for me, and the good news is that the hoppers and cicadas are still around. although their numbers are somewhat down, I find the trout can go after them even more aggressively than at the height of summer.
Due to the colder mornings, I personally wait until lunch before tying one on. As September heads towards October, I usually scale back the size of my terrestrial flies. The large cicadas and hoppers seem first to go, but the ants and beetles seem to stick around until the first good frost.
In previous years, I have still been able to catch trout on hoppers for several weeks after the naturals have all but vanished so there is still plenty of time to get some hopper action.
Fall mayfly hatches, depending on the river and region typically remain steady throughout September, blue winged olives are common on my local waters, in saying that I typically stick with a generalist mayfly pattern rather than trying to pin down an exact replica. Sporadic caddis hatches can also occur throughout the month but they are reliable.
Catch trout on egg patterns in September?
In rivers that do not have spawning salmon, September is a slow month for egg patterns. In my local trout rivers, I do not typically use egg patterns until the start of October. The main reason why is that the trout spawn does not usually begin until then.
Depending on water temperatures, and light levels the first trout to spawn in the fall are typically Brook trout, in colder streams they can spawn as early as September. Brown trout spawning usually begins from October onwards.
By the last week of September, I might start experimenting with egg patterns, but I generally prefer to hold off until the brown and brooks have had a chance to lay their eggs.
In rivers with salmon runs, especially ones located further north such as in Alaska there can be excellent egg fishing in September.
Fishing Streamers and lures for trout in September
Early September is not my favorite time of year to be fishing lures. The rivers are usually low and clear putting the trout on edge.
Later in the month, if there has been a fresh or two to raise water levels large numbers of migrating brown trout can start moving upstream. Rivers upstream of lakes can be incredibly productive during this period.
These trout, some of them large do not usually have food on their mind, but they are becoming increasingly aggressive and territorial. Out of anger, they might just attack any lure that swims by.
I like to fish large lures, I want the trout to see them, and to be annoyed by them.
So late September can be a great time for fishing large streamers, close to the bottom in the hopes of catching a brown trout as it moves towards its spawning ground.
Targeting stock trout in September
With slightly cooler temperatures, September is a good month for targeting stock trout.
Just like the rest of the year, stock trout readily take dough based baits such as power baits, this is because they grew up on a diet of fish pellets and that is what they know.
I have caught stock trout with stomachs full of pine needles, pebbles even clime. They are willing to try almost anything that looks like food.