Temperature scales and more temperature variations
Of course a desert is hot and a tundra is cold, but what about locations in between? There should be a more extensive variation of weather and the average temperature.
Temperature scales, like an Icon, displayed around the minimap would also be a neat Feature to see the Variation of temperature caused by weather or even spells.
Lee James Wood commented
the hotter the fire, the more difference. Maybe burn metal and catch things it would not normally catch on fire, on fire. Maybe explode things that would normally simply catch fire.
I like this, it's a level of depth IN the elements themselves.
Imagine earth had deeper earth tones, water had deeper zones, and same for void and darkness and light and whatever else there is. It could be visually distinct.