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It is Hot Out! Fish for Trout

Summer is hot in general, but August is really hot. Regardless of your perspective on any thermal phenomenon occurring on a global scale, the heat of these middle months is undeniable.

Trout aren’t big fans of heat.

Without getting all sciency, factors such as heat in the mid-70’s and the associated reduction in dissolved oxygen will put trout in significant distress. Created to be relatively resilient, they will hold on if they have to endure such conditions for short, intermittent stretches. However, if they are put into a situation where they must exert themselves – say, fighting at the end of a line – there is a good chance that they’ll die.

So, the common solution for conservation-minded anglers that place stewardship above sport is to lay off the fly fishing for a month or two. Good. Great, even.

But does that mean that fishing for trout is off limits in July and August? Are bass and carp the only fair game in the heat of summer? (As if these fish don’t have temperature thresholds…)

As is the case in most circumstances, if a “smarter not harder” mindset is employed the fly fisher can absolutely still fish for trout throughout the warmest times of the year. Here are three things to consider:

Springs in Summer

Although proximity to legitimate spring creeks is a luxury to certain parts of the country, having these unique watersheds as an option in the summer is excellent. The flows are almost always consistent in volume and in temperature, with only they worst droughts causing interruption to a very steady ecosystem.

What is more likely to be available to a broad swath of fly fishers is creek systems that are influenced by springs. Whether it be seeps (areas within the stream where spring water enters) or tributaries (small, adjacent streams that flow into the main stream), an influx of cold water can create a stretch of water that serves as a sanctuary during the heat. Finding these spots usually comes about through scouting: while wet wading in late spring you’ll definitely be able to feel these areas.

All that to say, these pockets of cold water can concentrate fish. Although this is good in milder heat, it can also create incredibly dense points of refuge during the hottest or driest stretches. Dozens of trout, stacked like cordwood with their noses in a little tributary are fish that should be left alone.

Thermometers Dropping

You’ve got barbless hooks. You’re carrying a rubber-bagged net. You’ll drive all the way to somewhere where summer fishing should be an option.

Why haven’t you shelled out a few bucks for a thermometer?

“It isn’t that hot outside today” is no metric for fishing conditions that are good for the trout. Similarly, “it is way too hot out today” is hardly a hard and fast reason to stay off the water. Many trout streams have thermal protection from riparian and overhead foliage. Even on the hottest days, a quick check of the thermometer might show that the ambient heat hasn’t impacted the water much.

Conversely, a steam that is usually fine might not be. Before the rod is rigged, before the waders are on, just drop the thermometer in for a few seconds. The result might not be NO FISHING… it might just be head upstream or into the next valley.

Time is On Your Side

Morning and evening are cooler. Fact. Again, it is hardly scientific, but think about how your body reacts to its temperature being raised by only two or three degrees. Shallow streams can experience significant thermal fluctuations throughout the course of a sunny day. The trout will feel that, and they’ll be wanting nothing to do with exerting themselves in the heat of the day. Once the sun goes down and things cool off a bit, they’ll be much more apt to feed and much less stressed by a quick fight.

Again, a thermometer is key in determining if the absence of the sun has cooled things off enough. Feeding fish aren’t an indication of fish that will survive a struggle unscathed.


Remember that fighting and handling fish properly and quickly are always key, regardless of the month or temperature. If anything, the extreme heat or cold of the air is cause for keeping fish wet as much as possible.

Summer is short. Taking a few extra steps can lead to some great fishing in August, but also can preserve the overall fishing throughout the rest of the year.

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