It changes how food, water and drugs work as well as how your body is affected by them. This mod and the next two listed are highly recommended to download together as the modders themselves have worked to bring them together in a way that makes sense, and so each mod actually affects the other.
Even better, it's not sunny one day and then rainy the next. The night itself changes too-it's darker now and the sky is changed as well, filled with a universe's worth of stars to gaze upon. There's even snow in appropriate locations, and rad storms when you think the desert couldn't get any harsher. Nevada Skies changes not only how the sky itself looks but adds weather, too! It offers sandstorms, rain, thunderstorms, cloudy days, more kinds of sunny days and a myriad of different clouds to look up and squint at.
Good work! Now you can start modding, but where do you start? Do you install major weather and sky mods that change how the entire Mojave looks? Or do you want to give yourself more perks from the get-go? Well, lucky you! You just found yerself a mighty fine list here partner. So you did yourself a favor and you bought Fallout: New Vegas for the PC.