I had a long post written out but it broke the 2000 character limit. Here is the TLDR version. TLDR: Siteground hosting detail and sign up pages look like monthly renewals are possible. When it comes time to renew hosting, you can't do anything less than a yearly renewal without talking to a live chat agent.

Even then, without pushing back, you are required to do yearly renewals.

Here is the hosting detail page, the account sign up page, and the ToS page.

http://archive.is/6kevN http://archive.is/zog1A http://archive.is/BMj7k