Microsoft Flight Simulator X: Steam Edition - World Environment 2012

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

World Environment 2012 is a weather texture enhancement package, which brings a new level of visual realism to FSX: Steam Edition.

This pack features over 250 new textures that significantly enhance the visual environment, no matter where and when you fly - adverse weather conditions become more visually intense and sunny skies more cheerful with World Environment 2012.

Once installed, these textures will be implemented in FSX: Steam Edition automatically.

Features:

New textures in high definition bring your skies, clouds and environments to life
Ultra realistic HD clouds for overcast, broken and scattered conditions
New and more realistic skies with horizon transition and visibility smoothing
New sunrise, morning, noon, afternoon, sunset, and night sky textures
Improved precipitation sounds inside and outside the cockpit
New lightning effects