The weather is tropical, with an average annual rainfall = 1811 mm (72 in) and driest month are June to September. In the dry, winter months (June to October) some portions of the Amazon are far enough to occasionaly receive cold weather fronts moving up from the Antarctic. These fronts, called frente fria or friagem, often bring extended periods of cloud cover and rain in addition to drops in temperature (sometimess down to 8°C, 46°F).