The Weather Graph Chart is one of the most visually appealing features of the Location Weather plugin. To display it in your weather view, follow these steps:

1) Select the Horizontal or the Combined weather layout, as currently it is available for these two layouts. 

2) Go to the Display Settings tab of the plugin. 

3) Now, go to the Weather Forecast Data tab.

4) Here, scroll down a bit, and you will find the Weather Graph Chart option. Enable it.

Refresh the page where you are using the weather view to see the changes. It will look something like below: