Snowfalls occur regularly in the winter in the interior North and Centre of the country in districts such as Guarda, Bragança, Viseu and Vila Real, particularly on the mountains. In winter, temperatures may drop below , particularly in Serra da Estrela, Serra do Gerês, Serra do Marão and Serra de Montesinho. In these places snow can fall any time from October to May. In the South of the country snowfalls are rare but still occur in the highest elevations. While the official absolute minimum by IPMA is  in Penhas da Saúde and Miranda do Douro, lower temperatures have been recorded, such as  by Bragança Polytechnic Institute in the outskirts of the city in 1983, and below  in Serra da Estrela.