Microsoft has just released a new video onto their Microsoft Flight Simulator YouTube Channel that reveals that the game will feature multiple seasons.
The video is titled "Let it snow!", and begins with an opening show over New York City in Autumn. We then see the city become slowly covered in snow as the season changes to Winter, eventually blanketing snow all over the buildings and central park. Microsoft Flight Simulator will use a huge amount of data from Bing Maps, and through Microsoft's cloud, it will be streamed directly to your PC to give you photo-realistic models of real Earth.
It should also be noted that Microsoft Flight Simulator will utilise real-time weather data, so if a storm is happening right above your house and you are wondering what would happen if a plane flew right into it -- you can answer that question in-game. Since Flight Simulator will be using real-time weather data, this would mean that when seasons are changing in real-life, we should see a reflection of that in-game.