Merlin Entertainments will open its newest UK attraction, the Sea Life Tower in Weymouth, on 22 June - a month ahead of schedule.
The construction of the observation tower, which has been undertaken by German ride manufacturer HUSS Park Attractions, has been aided by warm spring weather.
The 53m (174ft)-tall tower has been built on the town's Festival Pier and features a rotating gondola of 12m (39ft) in diameter, capable of accommodating up to 70 passengers at a time.
General Manager Craig Dunkerley said: "We were lucky with the weather in the early part of the construction schedule, and we're now so close to finished we have been able to announce an early launch with complete confidence."