Shrouded in a thick curtain of clouds that block much of the light from the nearby sun, Gendius I is still known to have extreme daytime temperatures that prevent most natural life from moving about the surface during the daylight hours.
Despite the heavy cloud cover, the atmosphere is thin and allows massive amounts of heat and radiation to penetrate to the planet's surface. Once reflected off the terrain, these elements remain largely trapped in the lower atmosphere by the dense clouds. Additionally, the extreme heat of the daytime sun evaporates almost all surface water, which leaves the ground dry and cracked; this, along with the radiation, has contributed to almost a complete lack of surface vegetation.
The creatures of Gendius I have evolved in such a way that constant radiation in low to moderate levels is largely ignored. In addition to having adapted to the ceaseless radiation, most of the animal life has become nocturnal, and those creatures which haven't still avoid being on the planet's surface during the hottest hours of the day.
During the nighttime hours, however, the planet becomes a completely different place. The temperature, while never reaching a point in which snow or ice could form, is considerably cooler than daytime temperatures. Torrential rains flood the dry, barren ground, and much of the animal life ventures out from its underground home to hunt and forage whatever food might be found. The combination of the heavy rains, hungry and aggressive predators, and latent radiation from the daylight hours makes the planet, even in darkness, an extremely hostile place to visit.