We use the OpenWeather API for our Pages Weather component:

In the component settings page editors can choose to show a title, the unit of measurement and whether users can select their own location (rather than the one set as the default)

If your site is hosted by us (SaaS), we can set up the API on your behalf during onboarding and make sure the component works as expected.
If this was not set up for you, please raise a support ticket so we can assist you further.
If your site is hosted by your team (on-premise), they will need to create an account with OpenWeather and add the API into the appropriate area of your Intranet: (Applications > Admin > System > API Keys)

Alternatives
Different weather components are available for free online if you are after a particular look or feature not available in the Intranet
These will provide code you can place into the Claromentis page embed component to display the weather information.
e.g. https://weatherwidget.io/