Formula using Dawn and a little bleach for awning...

Chlorine bleach is pretty harsh.

Use oxygen bleach (Oxiclean or generic). Hose and mop the awning first to get dust and loose dirt off, then a cup of Oxiclean in a bucket of water - use a mop to get the awning as wet as you can, then roll it up and let it sit overnight (or until the next weekend, if you want).