Before any plans can be made, you need to understand the basic conditions at the riverside. There is much more change in river conditions than in lakes and both bait fish and game fish will adapt to temporary conditions.
Perhaps the biggest single factor in the River fishing is River water level and the amount of its change. In the United States this information is easily obtained for hundreds of large to midsized rivers. A good source is the usgs.gov website.
Generally rising waters sends fish into the shallows where they will feed on new food at the waters edge. Falling waters create the opposite effect and rapidly falling water can cause difficult conditions. Many fishermen prefer stable conditions where game fish are more easily patterned. However with patience, persistence, and good notes fishermen can improve their catch dramatically by being knowledgeable about what to do in changing fishing.
Water Temperatures in a river do not dramatically change. Rather water temperature should be considered a seasonal effect, with a winter minimum building to a summer maximum. There are two powerful effects to water temperature
- Springs are nearly 50°F year-round. Thus, smaller waters do not vary nearly as much. A small spring feed trout stream in the North will only vary from perhaps 40°F to 70°F; while a major navigable river might vary from 33°F to 100°F.
- All waterways follow a seasonal pattern of warmth in the late summer and coldness in the early spring. Rivers in particular are similar in temperature versus depth (except for perhaps in the largest rivers). This obvious fact, creates a very different outlook to temperature than in reservoir or lake fishing. In lakes, water tends to creates layers; that can concentrate fish at a certain depth. Lacking this, we find the fish much more spread out in the water column; Thus we should be much more openminded about varying the depths of our presentation.