What does the rain, as Silas enters Opus Dei, seem to symbolize?

The rain, as Silas enters Opus Dei, seems to symbolize pain, suffering and depression that Silas has experienced in life. Also, since Remy has already shown some pity over the fact that Silas is being set up, the rain seems to foreshadow things to come. Silas is, at the very least, a pawn for the Teacher. At worst, he's likely to be murdered, like Remy. All of which is symbolized by the rain.