The climate can affect the types of dreams we see. Hot seasons and weather influence the brain to recreate corresponding dream imagery. However, sometimes it is possible to dream of contrasting images when the climate is different. This can be due to the dreamer desiring a different climate because they miss it. For example, a dreamer may desire to see winter, while living in a hot, summer climate, because of their love of snow.
If you love the rain and have been particularly happy with pouring rain, then you might dream of the weather being rainy.