macOS ships with scripting languages (perl, python, bash) that are easy to learn and are (generally) future-proof.
What information are you trying to get?
WU can be done, but it will depend on what you want ... they have an API, but access to it is limited, but some historical data can be pulled from the data export facility.
Weathercloud.net doesn't have an API so you would have to screen-scrape.
If you have a Meteobridge or other device uploading data to those sites, it is easier to write a script to pull data from that, instead of from the Internet.