Anyone here know how to change the 'Weather Settings' in navigation?

Mine forecasting Downey, CA when I live far from that. Anyone know how to fix this?

 

When you go in through the menus (not voice command), you should get a screen like below, which will allow you to select a different city. My understanding is that "Current Forecast" will show where you are (or where it thinks you are). You can select other cities from there.

Unfortunately, using the voice command "show forecast" will always pull up the forecast of where it thinks you are currently located. If this isn't correct, then I'm not sure that there's a way to fix it.