Have you ever wondered why a thunderstorm can sometimes turn off the trout bite like a light and other times it can drive them to a feeding frenzy? Well I did some research on this strange phenomenon and here is what I found. In moderation precipitation on its own has no direct affect on fish behavior, but the underlying cause (barometric pressure change) and its associated effects (cloud cover/air temperature change) does.

In general low pressure has a negative impact on trout and high pressure has a positive impact. With most fronts comes a drop in barometric pressure, so often times fishing will turn off right after a front comes through, and then when the weather clears from a high pressure system, the fishing will turn on again. Although it can take a day or so before the fish regulate and go back on the feed.

As for the rain itself it can be a good thing. Rain actually oxygenates the water, and in light amounts can stimulate feeding. This is because the atmospheric pressure stays high during a light rain; heavy downpours on the other hand are a sign of erratic and unstable atmospheric pressure and will usually terminate trout activity all together.