WATERCRAFT

How weather affects fishing

AFTER record rainfall in February and the hottest May on record, long-range forecasts are now pointing towards it being a scorching hot summer.

But does the weather really have as much impact on our fishing as we think?

And, if it does, what are the best conditions to look out for?

Light levels

Overcast days often produce great sport in the same way that fishing early mornings or late evenings can be good. Low light levels very often coincide with a spike in feeding behaviour for many species.

Invertebrates, the main food of most coarse fish, tend to hate light and only come to the surface when light levels are at their lowest, making them easier to catch. Predatory fish also find it much easier to catch their prey unawares when light levels are low. Such fish often have large eyes and are well camouflaged, enabling them to stalk prey fish much more closely.

Rain

Bites often seem to dry up when the heavens open, and this is especially true for predatory fish, such as pike. They use their finely-tuned lateral line system to hunt, but the drumming of rain on the surface interferes with its efficiency.

Rain does not have the same chemical composition or temperature as lake or river water, and so a heavy shower can affect the water’s chemistry.

Rain can have a cooling effect, and a temperature drop of only a tenth of one degree can stop fish from feeding. Rain is also likely to be more acidic and carry less oxygen than lake or river water, so this, again, can have an adverse effect on feeding.

Wind

The wind has numerous effects on our catches, some not obvious. A ripple on the surface can significantly reduce the light levels below, especially if the waves are at an angle to the sun. If, however, the waves are rolling towards the sun the light level may actually increase because more of the sun’s rays will be able to penetrate the surface of the river or lake.

Within a few minutes of a breeze picking up the oxygen level in the surface layers will start to increase as the bigger surface area and broken boundary layer enables more oxygen to be absorbed and more carbon dioxide to be released from the water. As such, in the summer months the onset of a breeze can quickly prompt fish to start going on the feed.

Fish will often feed more confidently in coloured water, so, as the windward bank becomes more murky, the fish will often get their heads down in earnest.

Whether or not the wind warms or cools the water depends on the relative temperatures of the water and the air. Generally speaking, a warm wind from the south or west is likely to be hotter than the water. Over a few hours this will mean that the windward shore will become slightly warmer than the rest of the lake. The converse is true if the wind comes from the east or north.

“The wind has numerous effects on our catches, some not obvious”