IMO the big fish bite EVERY day!!!! Just need to be where they are feeding!!! Most people say spring because that's when a lot of the females are carrying eggs and weigh more.... Fall both make and female are gorging themselves just like bears do getting ready for winter... ALL of these fish although maybe a little lighter during summer are all aggressively feeding every day during the summer!!!! Everyone just needs to be able to find where the big girls go during hot weather and long days of sunlight. This is just a guess on my part but summer fishing doesn't bode well with a high percentage of guys because they do not like to fish in deeper water nor at night!!!