The surface water warms up to the point that trout cannot tolerate it as the oxygen level is lower in warm water than cold water.
To remain in their temperature comfort zone trout swim deeper to be able to feed.
If there is no deep water to escape to, trout slow up, stop feeding or look for the coolest water they can find to lower their oxygen demand.
When the water cools in the evening and through the night trout will return to a normal feeding pattern.
If you catch a trout and want to return it, it takes longer for them to recover so hold them upright in the current in a stream or away from the shallows in a still water until they swim away strongly.
The best time to fish is late in the evening, through the night and early in the morning.
My son Chris and I fished Rutherfords Dam one evening this week and while there was a cool east wind blowing, the water was warm to the touch.
Usually, the water at the windward end of a still water is cooler than the leeward end as the warm surface water is pushed along which causes cooler water to come to the surface at the windward end, enabling trout to feed.
We fished at the windward end as the sun was going down and as the wind began dropping. We immediately saw rising fish and a few sedges were skittering on the surface.
I lost one fish on a nymph before putting on a sedge.
I was soon into another fish but this too dropped off.
The number of rises dropped off too so we decided to call it a day and as I wound in a trout seized my sedge and was soon in the net.
The following day I fished the Taieri and on the first pool that I fished I spotted a trout cruising along close to the bank and it nailed my diving beetle as soon as it saw it — a good start I thought.
It got hotter and hotter and it was a while before I saw any rising fish and even longer until I saw fish, I could get a fly to.
When eventually I found several fish rising beneath some willows a fish took first cast but I failed to hook it and over the next half-hour not a single fish had a go at a variety of flies presented to them — and finely presented too, I might add.
Wandering further upstream looking for less wary trout I saw a fish come right off the water to take a damsel fly.
I plonked the diving beetle in the rings of the rise and the fish was airborne again on the end of my line but not for long as it dropped off on the next jump.
But not to worry as there was another fish jumping a few metres further upstream.
