John Stillwell/ AFP/Getty Images

The countdown is on for Duchess of Cambridge Kate Middleton's July delivery, and with every public appearance the duchess looks more and more like a mom-to-be.

Today the duchess's seven-months-pregnant baby bump was on full display as she attended Queen Elizabeth II's annual summer garden party at Buckingham Palace.

PHOTOS: The Life and Times of Kate Middleton

As more than 8,000 partygoers dressed in festive hats circled the palace's grounds, Duchess Kate stood out in a lemon-yellow coat dress and cream-colored fascinator topped by a bow. The duchess also carried a nude-colored handbag that, when she held it clasped below her waist, clearly showed off her growing belly.

READ MORE: Kate Middleton's (Lookalike's!) Baby Shower

Duchess Kate, 31, appeared at the annual fete with her in-laws, Prince Charles and his wife, Camilla, Duchess of Cornwall, and smiled through the festive affair, gamely greeting other party guests clearly excited to meet her.

This year's garden party featured Olympians, Paralympians and officials from the 2012 Olympics in London, an event the duchess and her husband, Prince William, attended both as royal figures and as spectators enjoying the fun.

RELATED: Kate Middleton's Pregnant Fashion Frenzy

The Queen's garden party, a royal tradition since the 1860s, features its own special blend of tea, more than 27,000 cups of which the attendees were expected to enjoy today. Garden party guests also eat 20,000 sandwiches and 20,000 slices of cake at each affair, according to the Royal website.