In addition to Microsoft Flight Simulator's built-in ability to download METAR weather reports for most locations in the world and import that weather data into your simulated environment, there are additional softwares that can add ever increasing realism to the weather around you in the simulator.
The weather fidelity in Microsoft Flight Simulator is good to start with, but leaves a lot of flexibility for developers to add even more fidelity by using their own techniques for importing and representing weather system data. You will find the built-in weather to be multi-layered, and representing a wide range of weather phenomena and visual appearance. After-market weather services such as Active Sky are able to use higher-fidelity weather data, and import that information into the simulator while you fly. These after-market weather packages tend to support a higher level of complexity within the weather systems, as well as giving the user more control over their individual weather experience.
It will be impossible for you to judge the full weather capabilities of the simulator until you have established some experience configuring the software, and are aware of the expansion software that exists.