The Lord Mayor’s Hot Air Balloon Regatta will take place in 2021.

It is The City of London’s official ballooning event and an aerial extension of the classic Lord Mayor’s Show. Following dates for the 2021 Lord Mayor’s Balloon Regatta have been announced; June 6th, 13th, and July 18th, 25th, 2021.
Up to fifty hot air balloons fly across the city center of London every year to raise awareness and donations for the Lord Mayor’s Appeal. The official Lord Mayor’s Appeal hot air balloon, which carries both the Lord Mayor and Lady Mayoress, leads the launch.

The Lord Mayor's Hot Air Balloon Regatta - London Airport Transfers — The Lord Mayor’s Hot Air Balloon Regatta – London Airport Transfers

At 5:30 a.m. on Sunday, June 9th, the 2019 event launched from Battersea Park, with 46 hot air balloons filling London’s skyline. The flight raised £76,000 for The Lord Mayor’s Appeal, bringing the total raised in just four years to an incredible £251,724!
The 2020 Lord Mayor’s Balloon Regatta was postponed due to the Coronavirus crisis. Nevertheless, the Lord Mayor’s Balloon Regatta® is planned to return in 2021, and will once again launch from Battersea Park.