Topography affects climate because of its location. Some are far away like Antartica, so they don't receive that much sunlight. Also, there are places that not experiencing rain. For example, desert, desert is sandy and its very hot there, so it affects climate by heat, and it doesn't rain there. Rainforest are forest that is experiencing rainy days, because of the climate there, it is now called RainForest.
Hope this helps =)