The source of Earth's solar power: The Sun. Solar energy is radiant light and heat from the Sun that is harnessed using a range of ever-evolving technologies such as solar heating, photovoltaics, solar thermal energy, solar architecture, molten salt power plants and artificial photosynthesis.
1 The average annual temperature in Vienna, Austria is a little cool at 9.8 degrees Celsius (49.7 degrees Fahrenheit). 2  Mean monthly temperatures vary by 21.5 C (38.7 F) which is a below moderate range.3  The range/ variation of diurnal mean temperatures is 7.3 C (13.2 F).verage Temperatures in Vienna, Austria. 1  The average annual temperature in Vienna, Austria is a little cool at 9.8 degrees Celsius (49.7 degrees Fahrenheit).
The warm and pleasant summer months range from May to September with the summer peak in July and August. You can get warm and sunny days in April and October, as well as miserably cold and rainy ones during the summer, but thereâ²s always an element of risk with the weather in Austria.