Thousands of people are expected in Rhyl on Saturday as the famous Red Arrows and the last flying Bristol Blenheim bomber take to the skies.
The 10th annual two-day Rhyl Air Show will also feature a Battle of Britain Memorial Flight, including a Spitfire, Hurricane and Dakota aircraft.
The show will have attractions on the ground, including military vehicles and a Winston Churchill impersonator.
Events will start at 14:00 BST on both Saturday and Sunday.
Extra traffic is expected around Rhyl and on the nearby A55 road across north Wales and Denbighshire council are advising visitors to “to allow extra time for their journeys”.
A Team Raven formation aerobatic display team will start the event on Saturday and the first day will be ended by the Red Devils Parachute Team.
The last remaining Blenheim – that featured in the 2017 film Dunkirk – is a “real draw” before the Red Arrows close the air show on Sunday.
“As well as the Red Arrows, having the last remaining Bristol Blenheim in the world is a real draw for visitors and offers the chance to see a plane instrumental in providing cover during the Dunkirk evacuation,” said Denbighshire council leader Hugh Evans.
The full line-up includes Russian and German military aircraft from the Second World War and a gyroplane which can fly within a 100ft of the crowd.
Car parks at the Sky Tower, Morley Road, West Kinmel Street, the Pavilion Theatre and Quay Street in Rhyl are open but the town’s underground car park is shut for refurbishment.
North Wales Police has also warned that drones should not be flown in the area of the air show as it will be subject to a Restricted Airspace Temporary Order.
Trains between north Wales and London will be longer over the bank holiday weekend due to engineering work while Virgin services will only run between Holyhead and Crewe.