Fiscus Benjamin help

[Mags28]

Hi I have a problem with my fiscus has white water spots on leaves that turn brown could any one what is the matter

 

[Sheal]

You say water spots, has the plant been watered from above?

 

[Mags28]

It's outside in a pot haven't had to water it's winter

 

[Sheal]

Yes of course. It looks like sun scorch but being winter it may be a fungal problem, the leaves seem to have mildew too. Is the Ficus used to being outside over winter and what would be the minimum temperature overnight?