Het weer in Ouro Preto in mei

Brazil's forum notes that March brings less rain than February but still carries the tail end of the wet season's pattern - warm, sunny days followed by a real chance of a heavy afternoon or evening storm, sometimes intense enough locals have a name for it ('as águas de março,' the March rains). For Ouro Preto specifically, that matters more than it would elsewhere: the town's steep, cobbled colonial streets get genuinely slippery when wet, which is worth factoring into footwear and pacing choices while exploring the churches and museums on foot.

Forum posters describe mid-September through early November as one of the better weather windows for this part of Brazil - noticeably warmer and less humid than the April-May stretch some posters compare it against. The one clear caveat posters raise: the rainy season proper doesn't begin until around the first week of November, at which point Ouro Preto's steep, cobbled colonial streets are specifically flagged as becoming slippery and best avoided in heavy rain. September itself sits ahead of that shift, making it a comparatively dry, walkable choice for exploring the hilly historic center before the wetter November-January period sets in.