Kate Middleton and Prince William
Kate Middleton and Prince William Reuters

Kate Middleton has reportedly left Kensington Palace to join her parents at their home in Bucklebury, Berkshire.

According to Us Weekly, the heavily pregnant Duchess of Cambridge left the Nottingham Cottage residency, in the north of the Palace grounds, as it does not have proper air conditioning. The move comes after temperatures soared to an annual high across the UK on 13 July.

"It was just too warm in Nott Cott," a source said, "She [Kate] decided to spend the weekend with mum and dad. Much more comfortable."

It was previously reported that Kate, 31, will spend at least six weeks with Michael and Carole Middleton following the birth of her first child at their £4.85m Georgian manor.

Meanwhile, anticipation continues to grow about the birth of the royal baby, as Kate's due date of 13 July has come and gone.

Father-to-be Prince William attended the Jerudong Trophy Charity Polo Match at Cirencester Park Polo Club on Sunday 14 July. Initially the Duke of Cambridge was in two minds about whether to attend the match, as it clashed with Kate's due date.

"I think he was torn as, clearly, he wants to be with his wife at such an important time, but was all too aware how much the event raises for charities he is passionate about," an insider said.

Kate will give birth in the private Lindo wing of St Mary's Hospital in Paddington, London. The baby will be delivered by Marcus Setchell, formerly the Queen's gynaecologist. Princess Diana gave birth to both Prince William and Prince Harry in the same hospital.