The report by technical analysis firm DNV GL, for the UK's seabed landlord, the Crown Estate, found the UK's inter-annual variability of wind speed has a range of between 4-5.5% - down from the previously thought 6%.
DNV GL measured new regional wind speeds in project locations to find that the IAV was lower than the 6% figure originally thought from measurements taken in the 1990s.
As a result of the revised figures, DNV GL said the levelised cost of energy (Lcoe) could be reduced by up to 0.7%.
The results have been presented to the International Electrotechnical Committee (IEC) 61400-15 working group and the UK Wind Resource Group that were interested in the project, according to the Crown Estate.
"This report reveals a significant improvement in our understanding of the UK's offshore wind resource.
"We hope that industry will begin to reflect this reduced variability into their assessments to help create a more attractive financing proposition for investors and support continued cost reduction over the long term," said the Crown Estate's senior development manager Matthew Clear.