It can be either or. There's debate over whether weather is masculine or feminine, but most people seem to agree it's feminine. That's why i is used.
You will not be corrected for using e for weather though in everyday speech.
Yeah I think I actually was incorrect because I had "ann am Afraga" instead of "ann an Afraga". Thanks!
What makes this "tha i teth" and not "tha e teth"?