"There were no horses to be procured, and I must return by the lake; but the wind was unfavorable, and the rain fell in torrents." (pg. 187)
Nature and the weather play a huge part in this novel. The quote above was taken from Victor right after his wife was murdered by his creation. He first longs to go to the lake because whenever he finds himself in emotional distress, nature is the best cure. Also, "the rain fell in torrents," shows that something terrible just occurred. When the weather is gloomy or it is winter, the scenes in this novel show depression. In contrast, when spring rolls around and nature is alive and blooming, the characters reflect this through their happy actions and good-natured emotions. The beauty of nature seems to heal Victor and the monster in a way that no other man ever could even attempt.
This isn't just a coincidence that Shelley thought would be nice to add to the book. I know that the weather and the seasons affect me and my emotions too. I have also witnessed this change in my peers too. It is always a better day when the sun is shining because hope seems to fill the air.