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.
Algarve. Faro weather in in September (Faro, Algarve, Portugal): Still lots of sunshine, still hot, but cloudy days pick up, and some rain moves in. Day temperature hovers at around 26 degrees. The water temperature is now the warmest of all seasons, at a very comfortable average of 22 degrees.he highest daytime temperature in Faro in September 2014 was 30 Â°C. The minimum night temperature was 18 Â°C. Average day and night temperatures in Faro were 26.7Â°C and 20.3 Â°C.