You may set your default location by following the below steps:
Navigate to the dashboard or forecast page.
Click on the location drop-down.
Click on the heart icon next to the location that you want to set as the default.
From now on, this location will be your default location.
Tip: You may also select the pin icon if you have multiple locations. This will allow you to navigate to that location quicker, as it will be pinned to the top of the list. To unpin, simply click on the pin icon again.