I fish rain or shine, I personally seem to do better on overcast days and light rain. I fish shallow canals, on sunny days I don't get too much action after 10-11 in the morning,I suppose it's because it is so shallow the fish get hot and go for cover not sure though. At my favorite canal on an overcast day I almost always get some action, usually average 1 fish or bite an hour in the morning (knock on wood). The bigger canals here hold the big guys but the action is very slow paced reguardless of weather. The small canals hold great fishing as long as it's not too hot. My personal best (in the one year i've been carp fishing)from the small canals is 14lb. 7oz. and the big canals 27 lbs. 10 oz, both on overcast days. love them overcast days.