Hotter still is the core. In the sun this is thought to be 10 - 20 million degrees. These temperatures are due to the pressure caused by gravity trying to compress the star. It has to be this temperature for fusion of hydrogen to take place. Once fusion starts in a young star this adds to the temperature to ensure that fusion continues.
Weather in Lisbon in September. The average maximum daytime temperature in Lisbon in September is a warm 27Â°C (81Â°F) with low heat & humidity. There are usually 9 hours of bright sunshine each day, which represents 68% of the 12 hours of daylight. The average sea temperature in and around Lisbon in September is 19Â°C (66Â°F). Expect 26mm (1.0 inches) of rainfall across the whole of September with 6 days with some rain falling. Maximum UV levels will be high (6 UV index) at midday when the skies are clear.
Weather in Lisbon in September. Lisbon temperatures in September range from 18 to 27 and there is an average of 3 days of rain. Weather Facts - Lisbon in September. * The warmest temperature recorded in in September is 39Â°C. * The coldest temperature recorded in Lisbon in September is 12Â°C. * The average rainfall in Lisbon in September is 30 mm. Yearly Average for Lisbon. Max Temp.