It generally takes a few weeks of hot surface temps (18C+) before the deeper layers in the lake follow suit, and the trout subsequently get negatively impacted by the warm water. Trout are cold-water fish, so as walleye and pike fishing heats up through summer, stillwater trout fishing in low elevation stillwaters slows down, and as of a couple of weeks ago, much of it has bottomed out for the year.
There are fish to catch, be certain, but some major changes should be made to catch fish, and not cause them undue stress and harm. As I mentioned, trout are cold-water fish. Cool or warm water just doesn’t hold enough oxygen for them to survive there for long periods of time, and reviving trout in warm surface water is less effective than in cold water.
Trout in summer tend to hold in deep water during daytime hours. Yes, you can find trout in shallow, but this is the one time of year that I’ll often start my hunt in water over 12ft deep, no matter the time of day. Just before the August Long Weekend a friend and I fished a local lake, and we pushed off around 6:15am. The surface temp was already 23C. That’s very warm, and it was still July. I hooked a single trout in about 12 feet during the first hour, but aside from the odd rise, it was dead. We wound up finding and landing several trout over the next couple hours in 18-14ft of water before calling it quits at 9:20am when the air was a calm, stifling, and a sunny 26C; things weren’t going to get better! Grownup tip #327 –know when to call it a day.
During the heat of summer, spend the majority of your time on the water during morning and evening, avoiding the heat and brightness of mid-day if at all possible. Start fishing in 12-20ft of water, which can be daunting. Fast sinking lines help, but you need to be able to put them out there at least 50ft from the boat to have any appreciable retrieve. Remember not to force the cast. If you don’t use them much, take a half an hour and cast it in a park to get used to it before you head out. Use a fish finder to locate deep water weeds, drop-offs, or any other structure that could attract trout, making your task a bit easier. To avoid waiting upwards of 2 minutes per cast waiting for an intermediate line to sink, use a type 4-6 full-sinking line to reach the depths very quickly.
The “thermocline” is an important aspect of summer fishing. This is the layer of water that goes from warm to cold (from top to bottom) in a short vertical section of the water column. Water can go from say 17-11C in a small depth change such as from 16-20 ft. Trout will sit at this change, as the cool water is more hospitable and comfortable for them to stay for long periods. The depths I’ve mentioned above are good starting points, but you can locate the thermocline on each individual lake by cranking up the sensitivity on your fish finder.
Trout are able to feed with very little light, but with obviously a reduced emphasis on vision and specific feeding habits. When it comes to fly patterns, close is good enough, and movement counts. With that in mind, dark flies show more contrast than light ones, which aids us, and movement is felt by a trout’s lateral line. Colour is also a moot point in deep water that isn’t gin-clear. In murky or stained water, which let’s face it, includes the vast majority of our low-elevation stocked lakes, most colours are not discernible, or at a minimum severely compromised in as little as 9ft of water. As I said, close is good enough and you don’t have to carry 32 shades of olive leech. Woolly Buggers, leeches, attractor streamers, bushy wet flies, rubber-legged bloodworms, etc. all offer good contrast in low light situations, and look good enough to the trout to convince them to take a nip at your fly, if only to check it out.
Getting down to the fish is the key, and spin-anglers should note as well. Trolling a willow-leaf will not get you deep enough, nor will an unweighted flatfish. A large lead sinker placed above the latter will help, but the best option might be to cast a dark jig, let it sink, and twitch it back. Small spoons or weighted crankbaits are also worth a shot. Casting is best, as you can allow your lures to sink before retrieving them. Spin anglers have a notable advantage over fly anglers right now; lures put off more vibrations than flies, helping trout hone in on them. Sink times of lures like spoons or jigs are also a fraction of that of a fly line and fly. Use stealth, and get your lures down.
You may encounter some good rises yet, especially during calm evenings. It’s always exciting to get a fish or two on the surface, especially on lakes when it’s more or less infrequent compared to our wonderful streams. There are still quite a few mayflies around, and the caddis seem to sputter all the way through to early fall; always be ready for them. You don’t really need fancy flies: Adams, Mikaluk Sedge, Elk Hair Caddis, CDC Caddis, Pheasant Tail Nymph, and some generic soft-hackles for the caddis pupa.
During the heat of summer trout are stressed. Play them quickly, keep them in the water, and make sure they are ready to go with a couple powerful kicks before releasing them. A trout’s table quality is at a year-long low during August and early September, so keep that in mind. You may want to catch and release at least for the next month or so, allowing the fish to gain an extra inch or two by fall.
Key food sources during summer: baitfish, bloodworms, mayflies, caddis, leeches.
You may take advantage of the many hike-in or alpine lakes in the province. We have such a wealth of them, from the many in K-Country, to the underutilized water in Banff, Jasper, and Waterton. Trails are often good, and shore access is typically all you need. Check out the AFG listings and find a lake or two you’d be curious in checking out. Remember to always respect other anglers, give them space, and be courteous.
Have fun out there!