Climate and Variety
How often have you read a book or story on "the ice planet" or "the desert planet"? These things simply do not exist. Humans are immensely adapatable-- if there's a section of the world they don't live on, they will do their best to figure out how to get there. There are now people living on platforms on top of the sea, as well as people living in habitats under it. The Middle East, the most hotly-contested region in the world, is in the middle of a desert.
The reason why books and stories try to limit the climate to one type or another is because the author wanted to hit upon a mood or a theme by presenting the story in a setting that is somehow related to that mood. Who doesn't have some emotional response to a frozen wilderness or a lush, verdant field?
Get out a map or go to an international website like National Geographic. Look everywhere. Antarctica. Saudi Arabia. The rainforests of Brazil. The rainforests of Central California. Look at how the different climates behave and appear.
The first fifteen minute exercise is to write down all the different climates you can think of-- if you need to just say a city name, do it. Sometimes "Seattle" is more evocative than "northern damp temperate climate." Write these names down in a list.
Then, go through that list and write one or two words that describe how that climate, either the word itself or the way the place itself may have made you feel, if you've been there before. Try to stick to abstract adjectives; emotional words, if you can, but nouns are also okay.
Put this list in your notebook. Tomorrow, you'll really need it, so keep it handy.