"Heute ist es schön" is right, with "es" you implicitely mean "the weather". So, Lurker's second sentence is a full form of that : "Heute ist schönes Wetter."
"Es" means "it" in English.
When you find a big kettle of crazy, it's best not to stir it. --Dilbert cartoon
"Interplay.some zombiefied unlife thing going on there" - skavenhorde at RPGWatch