All fish are cold-blooded. Fish can’t maintain their body temperature at a constant level as do humans and other warm-blooded animals. The temperature of the surroundings influences the fish’s body temperature and bodily functions – including how much and when to eat. Lower water temperatures slow fish body movements and decrease food intake. Understanding these biological functions allows adjusting lures and baits with slower (cold water) or faster (warmer water) retrieves. Different conditions are often related. Many freshwater fish such as bass are most active during the early morning and late evening hours. Fish find the reduced light levels during these times more comfortable than the bright sun of midday. Less turbulent waters (less wind) in lakes and ponds during those hours also allow fish to cruise the shallows searching for food on or near the surface.
Morning sun warms the shallows, creating more comfortable water temperatures for fish to feed. Late morning is best when the sun has had more of a chance to warm the shallows. This is particularly true during early spring in shallows with dark or mud bottoms since dark areas absorb heat more rapidly than light sandy bottoms. Warm water temperatures make forage food more active and available to game fish on cool early-spring days. On hot sunny days, fish move to cooler, deeper waters to stay comfortable. Heat affects not only when to fish but also how to fish. High heat conditions make shallow and top water lures and bait best only in the early morning and late afternoon when cooler temperatures and lower light levels allow fish to cruise the shallows for meals. In midday, hot water surface temperatures, decreased surface oxygen and occasional increasing winds cause fish to move deeper. In these conditions, deep fishing baits, rigs and lures are best.
WHEN TO FISH
Experienced anglers will tell you that there are "best" times to fish. These "best times" can be related to the amount of sunlight, to warming trends, to depth at which fish are found, to storm and weather patterns, to wind, and to tidal flows when saltwater fishing. Thus, WHEN to fish can also affect and be affected by WHERE to fish.
Too many hot days during the summer can adversely affect fishing in shallow lakes, ponds, and rivers since the higher water temperatures can reduce oxygen in the water and cause fish to become sluggish.
VARIABLE WEATHER PATTERNS
Wind can play a large role in fishing success. Wind pushes bait to the far shore, with bait followed by game fish. If fishing from shore on a windy day, fish where you have to cast into the wind. If fishing from a boat, cast with the wind on a sheltered shore. Storms and changing weather patterns affect fishing success since fish are keenly attuned to changes in barometric conditions. With many fish, feeding increases during the hours immediately before a cold front, but slows during and after a storm or front hits. Fishing after a cold front is poor and continues to be poor for a day or two. Warm fronts cause surface water temperatures to increase. Such fronts often put fish into a feeding mode. This can be particularly true in the winter, when a warming trend can cause otherwise sluggish fish to start feeding actively. Most of this feeding activity is on or near the warm surface. Cloudy days improve fishing since the clouds prevent light penetration. Overcast skies cause fish to cruise for food more than they would during bright days when they tend to hide and stay close to structure. On overcast cloudy days, fish are less likely to be on specific structure spots or areas and more likely to be scattered throughout a waterway. Another good time to fish is during a light rain, especially a warm spring or summer rain. Rain can help you hide from the fish since the rain breaks up the view that the fish has through the water surface. This is true whether shore, wade or boat fishing. Rain also washes insects and bait into the water, with this extra food creating a feeding binge for fish. Warm rains quickly warm the water to cause these feeding periods. Hard rain conditions are a poor time to fish since heavy rains can muddy the water, make it difficult for fish to find bait or lures, and also cause heavy runoff which can clog their gills. The increased water flow in rivers from any rain increases current flow and makes it difficult for fish to maintain a comfortable position in the river. High water levels can also create rapids, waves and unsafe fishing conditions. If there is any lightning or possibility of lightning, you must get off of the water in your boat or immediately away from the water if wading or fishing from the shore. Safety must come first in any fishing situation.
SALT WATER AND TIDES
In salt water, tides affect water level so that a shallow area that might hold fish and be a very good spot to fish during a high tide might be a bare mud bank during low tide conditions. Similarly, a slough – a slight depression in the bottom - that might be perfect for bottom feeding fish such as flounder during a low tide situation might be too deep and difficult to fish on a high tide. Running tides (rising or falling) are best since they cause bait to move and provoke active feeding among coastal fish. Checking changing tides and the best times and areas to fish is also important when fishing in brackish water – coastal water that is a mix of salt and fresh, yet still affected by tides. Brackish water is found in most tidal creeks and rivers along all coasts and can affect both saltwater and some freshwater species. Since tides and movements are so important in saltwater and brackish water fishing, check for daily tide information in your local newspaper or at your local fishing shop. Tides raise and lower the water level approximately two times per day and affect where fish are located and how they feed. The timing of a high or low tide changes daily and is also different for each coastal area. The best fishing is almost always on a rising or falling tide – not the dead low or dead high when there is little or no water movement.
Determining the best time to fish requires checking on many fishing factors and outdoor conditions. The key to fishing success is to learn about fish and how they live. Try different tactics in your fishing to make each day of fishing a great day.