Complex sentence: Cuiabá is famous for its searing heat, although temperatures in winter can arrive sporadically at, indeed atypical, caused by cold fronts coming from the south, and that may only last one or two consecutive days, to then return to usual heat.
Split into simpler sentences: Cuiabá is famous for its searing heat, although temperatures in winter can sometimes reach. This is atypical, caused by cold fronts coming from the south, and may only last one or two consecutive days then returning to the usual heat.