The single most important detail in summer trout fishing is water temperature. If it is warmer than 68 degrees, either stay home or fish for something else (my preference is ALWAYS the latter. There is more to fly fishing than trout. If you have the time to fish, use it!). How can you figure out when the water will be cold enough? I have a pretty simple plan of attack. Let's start with freestoners, because the plan is a little more complex for them then the state's two bottom release tailwaters.
-Check the weather.
Find a night in the 50's. Even in July we do get those night time lows sometimes. The morning after that nighttime low of 56? That's when you go. Most often those nights happen after a cold front, and if you are lucky that cold front brought in rain and cloud cover. That is a recipe for perfection. Watch for that weather, get out on the river the morning after.
-Check USGS gauges.
Don't use Water Data? Do you live under a rock? Any fisherman that wants to be effective should be well versed in using waterdata.usgs.gov. Three tips for using Water Data to pick the best times for summer trout:
1. Not all river gauges have temperature readouts. If they do, keep your eyes glued on that graph leading up to your trip. The magic numbers are 60-65. That's the range you want. It doesn't have to remain in that range all day, but you best carry a thermometer and leave before the temp tops 68.
2. If the river you want to fish doesn't have a gauge, and most don't, look at the gauges for other river in its vicinity. This will never be a perfect metric. But if every other stream in a region is flowing below average and warm, you can safely assume the one you want to fish is too.
3. Use the gauges in conjunction with weather forecasts. If you can, compare water temperatures to the air temperature and amount of sun at the same time. Some gauges record air temperatures and precipitation which is a very useful. If the stream is 70 degrees at 4:00 on a sunny 88 degree day after a thunderstorm the previous night, you can just about bet it will be that temperature any time you see those conditions in the near future weather forecast.
-Understand your river's habits.
Knowing a river is vital. Where are the springs? Is there a lot of shade to keep the water cool in the upper river, or are there a lot of open areas? Are there a lot of long, slow, shallow sections?
Sun on the water is no good. Lack of springs or cold tributaries is no good. Slow water, also no good. These things dictate where you should fish a river and if you should fish it at all. Most streams will have colder headwaters and warmer lower stretches in the summer. Just because you see that a USGS gauge way down the watershed is reading 75 degrees doesn't mean there isn't cold water to be fished in that river. On the other hand there are a few streams that get colder the lower you get downstream. My homewater behaves that way because it is fed in a couple places far up the watershed by shallow ponds. Springs supplement the flow as it wanders downhill, dropping the temperature as much as 8 degrees in 4 miles. Find all day shade, find fast water. That's where the good trout fishing is going to be. A word of caution: isolated pockets of cold water in a river that is too warm overall should not be fished. Those places are refuges for stressed trout. Pressuring those fish is morally questionable. If the temperatures are not reasonable on both sides of the river and consistent up and down a 100yd stretch, don't try to catch trout there. Some streams stay cool almost all summer despite being freestoners. Most are small, but find those streams and you are golden. Following these rules may mean you make a number of visits to rivers without trout fishing them. That's all part of the game. You will come out of it a better fisherman. Get to know the river now and you will waste less time fishing it at the wrong times in the future. It is all worth it in the end.
-Fish at night.
Lower, warmer summer water will push more trout into nocturnal mode. Sometimes to a degree that it is next to impossible to catch at midday but almost easy after sunset. Remember that it takes time for water too cool down so it may be as late as midnight for water temperatures to drop appropriately in a freestone.
Water is always warmer lower in the water watershed in our tailwaters. My recommendation is to start early as far down the river as you want to fish and work up. Even with cold water high sun makes trout shy. So, if you are going to fish between 9:00am and 5:00pm, shadows are key. Overhanging trees, cut banks, woody debris... you should focus on those structures anyway but on a mid summer day you wouldn't do badly if you only fished that stuff. Fishing shadow lines during the summer has produced some of my best streamer and dry fly trout.
|A Farmington shadow line brown. Photo Courtesy David Gallipoli|
Opposite to night fishing freestoners in the summer, tailwaters often require hotter, muggier nights. Fog can be an issue though. Fog suppresses hatches and can put an end to a night bite. One way to work around that is to tightline nymph a huge black nymphs. That has saved me from a skunk more than once.
It is an oft repeated rule that longer leaders, lighter tippets, and smaller flies pay when fishing in the summer. But I frequently stray from that thought process in the exact opposite direction. I'll leave you with one last thing to try for summer trout: Fish the hardest, frothiest holding water you can find with a small frog pattern. You just may be surprised by how big the trout you bring up is.