Anyone know if there's a term for when you use the weather to create a certain mood/feeling? Also in a picture about war (negative image of horrors of war) & rain was used to create an ambiance, how would you describe this ambiance? like dull, dismal, any other words/descriptions?
'Pathetic fallacy' is a term used for this sort of thing. It involves the idea that human emotions are transferred to inanimate objects...eg the weather.
Another possibility is 'personification', where one might speak of "winter's icy fingers".
'Anthropomorphism' is similar, but it is generally used to give animals - rather than inanimate things - human characteristics.