Rain often coincides with low atmospheric pressure, so there is usually good feeding at the time of rain.
What I'd like to know is that although when rain starts, it's a good thing for fishing, and when rain stops seems to me to be a good time, too. But how about prolonged rain? There is only so much a fish can eat in a day! If its been raining for 20 minutes, does the advantage start to dwindle?
Also, does the type of rain matter? Is it just the heavier, the better, for oxygenation purposes, or can there be too much vibration and disturbance that sends the fish into lie-low mode? And, is there any advantage when fishing in drizzle?
One day it started raining, and it didn't quit for four months. We been through every kind of rain there is. Little bitty stingin' rain... and big ol' fat rain. Rain that flew in sideways. And sometimes rain even seemed to come straight up from underneath. Shoot, it even rained at night...
-Forest Gump