The weather is probably starting to turn cold where you're at. It is where I am. However, as the tip last week pointed out, this really shouldn't be a deterrent to you getting out and catching fish. Here are a couple of things to remember when fish get cold:
Like you learned in Jr. High science, or whenever (I can't really remember), fish are cold blooded creatures and their biological functions, including metabolism and consequently feeding, generally slow down when the water cools. This makes it important for you to take advantage of the fewer opportunities you may get to present your fly to feeding fish.
First - make your presentations smaller. With a few exceptions, most fish prey, whether it is invertebrate or vertebrate, is smaller in the winter. If you trout fish, concentrate on midges, small mayfly nymphs, and small scuds or sow bugs.
Second - slow your presentations down. Cold fish simply can't move as fast and so if you fish streamers for trout, bass, or other species be sure to move your offering slower than you might at other times and usually get it deeper.
Third - make sure that your presentations are very accurate. Cold fish are not likely to move as far to intercept a nymph or to chase a streamer. Sometimes you just have to feed them by drifting the fly right into their mouth. This takes some practice but you'll be well rewarded.
Get out there and try some of these things this Fall and Winter. I'll see you on the water!