The Simple Answer :   The color of a star's visible light indicates its surface temperature: a relatively cool star glows red (longer wavelength), and very hot ones glow â¦ bluish-white or even blue (shorter wavelengths).
Over the course of the year, the temperature in Shetland typically varies from 37Â°F to 59Â°F and is rarely below 30Â°F or above 63Â°F. The warm season lasts for 82 days, from June 24 to September 14, with an average daily high temperature above 55Â°F. The hottest day of the year is August 6, with an average high of 59Â°F and low of 52Â°F. The cool season lasts for 133 days, from November 26 to April 8, with an average daily high temperature below 46Â°F.
Averages for Venice in September. WEATHER LOWDOWN. September sees temperatures begin to decline slightly, however it is still very warm and there is still a lot to do. The average temperature still reaches a high of 24Â°C (that's about 75Â°F), and only gets as cool as lows of 14Â°C (about 57Â°F) at night. Shirts and pants or shorts should be adequate, but do bring a cardigan in case of a breeze. There are about 12.5 hours of average daily sunshine.