FIRST QUESTION: Why aren't there seasons in The 100 (winter, summer, fall, spring?) SECOND QUESTION: also how come deserts, snowy scenery, and forests are all close together in the same area? The desert where Jaha first landed on earth (which is near the solar panels) is right beside a lake which he goes across to reach A.L.I.E's mansion and beside the mansion are snowy mountains and forests.....this doesn't make sense....how can so many environments be so close together with different weathers? Aren't we talking about NEW YORK HERE???? one little island????
So far all the events took place during a period of less than a year, roughly in New York area.
Given that this is a post-apocalyptic setting, we don't know how the radiation and nuclear winter effected the climate and the pass of seasons.
We know that Earth landscape vastly changed in the last century. For example, the desert you mentioned located where NY city stood thus is likely not a natural occurrence, and in the Pilot Clarke noted that the river the crossed isn't on the old world map.