Some streams reached 24degC but luckily a few cooler days dropped the temperature to below 20degC.
Trout activity is reduced as the temperature rises above 20degC and they look for the coolest parts of a stream and where more oxygen is available.
The bottom of a deep pool is cooler than the surface and there is more oxygen available in ripply water.
They also frequent shaded areas, under banks or bankside vegetation.
So, when fishing, do not cast randomly, instead look for the spots where trout will feel most comfortable.
Most waters are very low at the moment, which in one way is an advantage as there is less water and trout are more concentrated in the likes of the spots mentioned above, so the chances of catching fish are much better.
I watched some nice trout in the Water of Leith the other day and they behaved as I have just described — either lying in the shade, in the ripply water or staying deep in a pool, all within a few metres of passers-by.
Murray Smart and I fished the Mataura at the weekend. The water was low and clear and it was a hot fine day and, pleasingly, there was little wind.
I started on a section that I have fished many times over the years and it is probably the area that has changed the most in that time.
It is extremely unstable and is braided with the extreme easterly channel some 200m beyond where it used to be and trees that used to stand on the east bank are now on the west bank.
Unstable areas of riverbed do not produce as much trout food as stable areas, therefore there are fewer trout there — and so it turned out.
I fished through all the channels of this area and although I caught the odd trout they were not there in numbers.
In the afternoon, I fished a stable area of river.
There were a lot more trout, especially on gravel drop offs, where water flowing through the gravel returns to the surface water and is cooler than the rest of the channel.
This cooler water stays deep, and allowing a nymph to fish through the deep run below the gravel turned out to be very productive.
I usually fish two flies when fishing the Mataura, a weighted size 12 hare’s ear nymph on the point and an unweighted size 14 of the same pattern on the dropper.
Not surprisingly, the majority of fish were caught on the weighted version.
Warm water conditions are not conducive to daytime hatches of mayflies so there are not many rising fish, although there was a brief fall of spinners which brought a few fish to the surface.
They were difficult to get on to, probably due to leader or line flash in the bright conditions.
At least, that is my excuse.
