Summer

Summer is one of the Seasons known in the Great Cavern of Aman-ya.
Following the creeping disappearance of snow and ice and the rejuvenation of nature in Spring summer is a time when the true heat of the Greenbright Moss starts to show.
After flowering in Spring the moss' ability to retain light and heat increases significantly which combined with a greatly increased heat emanated by the ground itself causes the warmest season of Aman-ya.
Summer within the Leshivoi Forest may be a time of plenty, both in natural resources and abundance of horrifying predatory creatures but within the City itself it is also a time marked by sweltering conditions and the fetid smell of the Three Serpent Rivers and Lake Aphon festering in the heat.
The water levels in the rivers which is laden with biomatter and industrial exhaust output all year around sink making the disgusting stew much more concentrated and turning all areas remotely close to bodies of water into stink-ridden hellholes.
The way the cobblestones and built structures spanning many miles trap the heat doesn't help and as such summer might just be the second least favourite season of the people of Styx, right after the deadly freeze of Winter.