Caught on Vickie’s Grizzly Bug

Water temperature is a critical factor in dictating feeding behavior. Understanding how water temperature affects trout feeding behavior provides valuable insight into your presentation strategy. Since water temperatures vary by season and the time of day, give yourself an advantage by including a water thermometer in your tackle bag.

The warming waters of spring trigger an increase in trout metabolism. As trout metabolism surges, so does their desire to feed. Based on my experience, I find the following temperature guidelines accurate predictors of trout feeding behavior and use them to plan my presentation approach.

Water Temperature Dictates Trout Feeding Behavior

40° F or lower: I find trout located next to shallow shorelines midday when water temperatures are warmest. Trout are relatively inactive at these temperatures because their metabolism significantly slows down. They eat infrequently and require a long time to digest food. Lethargic trout will not expend energy to chase flies. When they do feed, the window of opportunity often is very brief, typically midday.

41-49° F: As the water temperature approaches 50°, trout become active. However, you should slow down the speed of your retrieve. When fishing small pupa patterns in under 50° water, use slow 6- to 8-inch pulls with a definite pause between pulls. With larger suggestive patterns like leeches or buggers, use slow 8- to 12-inch pulls or slow hand retrieves.

50-60° F: Trout become active and feed aggressively. All forms of presentation are equally effective. Large trout will feed along shallow shorelines at sunrise and sunset and favor low light conditions while smaller trout will feed all day long.

61° F and above: Target shallow shorelines at sunrise when the water is at its coolest. Trout will feed briefly in shallow water before the sun’s rays penetrate the surface. As the water temperature continues to rise, dissolved oxygen levels fall. As a result, trout will move deeper where oxygen levels and temperatures are more comfortable.

While trout prefer water temperatures below 61 degrees, warm water species such as bass, perch, and crappie thrive at these temperatures. This is a good time to target those warm water species.

Bass caught on Grizzly Bug

At 68°, rainbow, brook, and brown trout begin to experience stress. When water temperatures exceed 68°, limit your fishing to early mornings and late evenings when water temperatures are cooler. Fishing above this temperature increases the risk of trout mortality.

How quickly the water warms depends on region, elevation, and seasonal influences. However, even the smallest change in water temperature can have a significant impact. Arming yourself with a water thermometer will enable you to track these changes and adjust accordingly.

Fish finders typically measure water temperature and depth. I have tried several and can provide recommendations based on my experience.

If you would like more information, send me a note.

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