The default behavior in Vim when you save a file is to also put temporary files in the save directory. I'll explain how you can stop it from doing this. (I don't know Vim that well, but the following works).
What happens is that if you save a file called 'weeklyReport.txt' it also stores a temporary file with the same name appended with a tilde 'weeklyReport.txt~'. It also stores a swapfile there.
I found this really annoying, as it makes it awkward to scan the list of files in the directory (and the files were getting into my version control system - and yes, I'm sure I could find a way to avoid them getting in there, but I think the better solution is to not have them in the directory in the first place).
Here's a solution I found (I'm using it on Windows, but the only difference on other systems should be the file system syntax for specifying directories).
Open or create your settings file.
Here's some deails if you're not familiar with doing this.Add the following lines to it (it shouldn't matter where):
When you install Vim, you've effectively installed two programs: Vim (the terminal version), and gVim (the GUI version), and each has its own settings file. For Vim, it's <VimDirectory>/_vimrc. For gVim it's <VimDirectory>/_gvimrc.
A note on what I mean by <VimDirectory>: the actual exectuable files are stored in a directory containing the vim version number - on my computer it is C:\Program Files\Vim\vim72. This is not the <VimDirectory> I'm referring to - the one I'm referring to is the parent directory of that, in my case C:\Program Files\Vim
" turn on backupThis will store the tilde and swap files in c:\temp - you can change the directory location to wherever you want.
" Set where to store backups
" Set where to store swap files
I found this soultion here, via this, and that via a google search.