Argentina's climate ranges from subtropical in the north to humid and steamy in the centre, and cold in the south. The upper Andes region has erratic rainfall, flash floods in summer, searing heat, snow at higher elevations, and the Zonda - a hot, dry wind. The lowlands receive sufficient rainfall to support swampy forests and upland savanna, but rainfall decreases from east to west; shallow summer flooding is common in the east. The winter dry season is pronounced, and the summer heat can be brutal. The flat Pampas areas are also vulnerable to flooding. Patagonia is mild year-round in the east and glacial in the south. Patagonian weather ranges widely during the year, from relatively temperate in the northeast to glacial along the Andes to fairly chilly in the far south.