Ive just put together a basic module to display PWS data from Weather Underground since API’s are now only available for free to PWS owners.
https://github.com/saabman/MMM-WunderGround-PWS-Observations/
It just displays the current data from a specified PWS and you can select what data is displayed.
@harney thats a pitty the BOM doesnt have close data for your site.
I have found that all the regular weather providers (Open weather, darksky etc) forecasts and observations are less than adequate for Oz.
So I have been reworking the Weather Module from WallberryTheme to use Aus govs BOM data. getting observations was easier enough as they provide that in JSON format which makes it some what easy but they only provide XML data for forecasts and the format is different for every site 
so my plans to “release” my module have stalled. because it has to be customised for each site.
yes the XML issue was a problem but I got around that by downloading the XML then as sdetweil suggested using XLM2JS to convert the file to JSON which I could ten search for the relevant fields unfortunately its not very tidy and needs customizing for each site.
IF you want to have a look at how Ive done it the files are here
https://github.com/saabman/WallberryTheme/blob/master/WB-weather/README.md
I am not by any means a programmer - just kept hacking away at the weather module till it did what I wanted - Im sure there are better ways to do it… hopefully it is help full any way
Unfortunately BOM lately has made changes to their site which is preventing accessing their data claiming it’s scraping but they provide a JSON file which I’m accessing (for part of it anyway) so my module no longer works- I’ve changed things a couple of times to circumvent the issue but it keeps coming back so I’m going to look at other ways to access the data. One that looks promising is WillyWeather. It is a paid service based on the number of access’s billed monthly. But it appears to be very cheap - It looks like for one Magic Mirror accessing data from one weather station and radar image works out at less than $10 a year.
When accessing the BOM currently they return a message to fill in a request form and some one will make contact - I filled in their form a couple of months ago and am yet to receive a response. Maybe when they get the servers sorted out things might change….