I am a great believer in air pressures effects on fish behaviour.I wont go into my theories here as that is all they are. However the facts that I have noticed are as follows.When Pike fishing in the winter all of my best days Piking(when I say best I mean numbers of fish caught as opposed to just a solitary big fish) have coincided with high pressure.The change to high pressure seeming to be the key.I have also noticed that during these conditions that the trout in growing on cages tend to feed harder.Why? don't know just that 35 years fishing has shown me this.Fish appear to be able to detect an iminent change in pressure,both up and down.When out fishing the pike have either just switched on or off and when looking at the barometer the pressure has indeed changed.High pressure in winter tends to bring clear skys with the resulting frosts and no wind.Low pressure at the same time of year is assosiated with overcast skys,rain,wind and more milder temperatures.Winter Carp fishing often apears better in low pressure.As allready mentioned by Stephen settled weather seems good, but I have found this best true for fish other than Pike.I gave up keeping detailed diaries a long time ago.My reasoning being that if any factor was that important it would make it self blatantly obvious over the years.Air pressure, for me at least, has done this.Would be most interested in other peoples views and experiences on this subject.