To further clarify:
www.bom.gov.au is HTTP only. It will fail to connect if you use HTTPS.
reg.bom.gov.au is an HTTPS version of www.bom.gov.au. It seems to be staying, but you have to know to use that address.
weather.bom.gov.au is a newer site with a much better design, and supports HTTPS. It is being retired.
Obviously there are a million third party weather services/apps but they all use the BOM's data, at least in Australia.