Winter for most parts of South America is the rainy season with water levels rising significantly causing lagoons and rivers to merge together into one large flood plain for much of the Amazon Basin. Rain is daily and comes down very hard and is nothing like anything experienced in the US or Canada. In fact, the rains are very similar to the monsoons in India.
The higher water levels increase the Peacock Bass’s habitat, which makes locating the fish much more difficult and can often be fruitless, other than catching a cold.
If you are going to venture out during winter, casting is preferred over trolling and lures are preferred over bait as live bait is difficult to keep alive and obtain. Once your hook is set, Butterfly Peacock Bass will put up a strong fight, making repeated short jumps and they do not give up when they are close to the boat. The minimum line strength is 20, but in most situations, 40 pounds is recommended as the big lunkers can exceed 30 pounds and are tough to land on 20 pound test line.
Read more here: http://bassfishing-gurus.com/butterfly-peacock-winter.php