Summer is now truly upon us with the longest day of the year in the Northern Hemisphere occurring on June 21. Since the Winter Solstice in December, the Sun has been rising higher in the sky each day, but on June 21 this behaviour stops and the sun is said to “stand still”. The word ‘solstice’ is derived from the Latin solstitium, from ‘sol’ (sun) and ‘stitium’ (to stop).