When will summer end in 2021?
SUMMER is here and so are the long evenings, beach trips and sizzling temperatures. As per the astronomical calendar, summer will end on Wednesday, September 22. This different to the end of British Summer Time, which saw the season begin on Sunday, March 28 when the clocks went forward an hour. On Sunday, October 31, the clocks will once again go back 60 minutes. But usually, when talking about the end of summer, it is the astronomical calendar being referred to. This is determined by the Earth's axis and orbit around the sun. The start of the astronomical summer was marked with summer solstice on Monday, June 21. 2 Summer began on June 21 this year Credit: Alamy  But this doesn't mean that it falls on the same date every year. The summer solstice can occur between June 20 and June 22 each year - depending on when the sun is directly over the Tropic of Cancer at midday. It is the day with the longest period of daylight and the shortest night of the year. This is because the tilt of the Earths axis is most aligned with the sun, providing us with the most daylight of the year. After June 21, the start of the summer season, the nights will begin to close in as our planet rotates with the northern hemisphere tilting further from the sun. Temperatures are usually at their warmest this time of year, even after the sun has gone down. Most read in News Exclusive SHARE B&B Harry to stay at Frogmore Cottage with Eugenie when he comes to unveil Di statue NOT LOVIN' IT Six McDonald's workers hit with Covid at fast food joint - and it stays OPEN Exclusive THAT'S SOME HAPPY MEAL! Maccies forced to close after travellers 'caught having sex in loo' BIRTH RIDDLE Mum who 'gave birth to 10 babies' in psychiatric ward after inventing story HIGH ALERT Two schools in lockdown after teen stabbed as cops swoop to arrest boy, 15 HEIR'S COMING HOME Harry 'to return to the UK in the next 24 hours' for Diana memorial  After summer solstice, days do get shorter - but this isn't noticeable for several weeks. Summer days slowly become shorter as the length of daylight hours begins to slowly decrease. It's because after the summer solstice, the sun's direct rays start to move southward from the Tropic of Cancer towards the equator.