Change background based on rule

Is there anyway that I can have the background image change based on weather conditions or certain days of the week. Or will I need to just create a duplicate dashboard with the different image ?

The whole dashboard’s background? Not at the moment, but you might be interested in casting a vote for:

Support for Variables in Media Tiles

I suspect that if we put in the work to support variables in Media Tiles, the same concepts would transfer over to dashboard backgrounds.

You might also be interested in the Weather Widgets: Custom Tile collection by @Michael – there’s some neat options in there that can display different background images (in a weather tile) based on the weather and a new weather clock that displays conditions.