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.
Overall, September is still warm, with a gradual decrease in temperature as autumn takes its hold. Around September 1, averages are at 24Â°C (75Â°F), with highs of 29Â°C (85Â°F) and lows of 19Â°C (66Â°F).By mid-month, averages are 22Â°C (72Â°F), highs of 27Â°C (81Â°F) and lows of 63Â°F (17Â°C).verall, September is still warm, with a gradual decrease in temperature as autumn takes its hold. Around September 1, averages are at 24Â°C (75Â°F), with highs of 29Â°C (85Â°F) and lows of 19Â°C (66Â°F).