Weather problems that caused disruption to flights over the last few days of August also hit Isle of Man Airport passenger figures for the month.
Passenger figures were down by 3,670 over August 2008, with over 65,500 passing through the terminal.
The predicted decrease of 3.5% turned out in actuality to be a 5.3% downturn.
The result has disappointed Airport Director, Ann Reynolds, as recent months had indicated that month-on-month decreases had substantially reduced.
"Whilst the economic downturn continues to affect the whole of the aviation industry" she comments, "we were hopeful that our peak month August would reflect the recent trends of a recovery in passenger numbers.
"The Island, like the UK as a whole, has not experienced the best of the weather during August and this has perhaps turned people’s heads towards warmer climates, despite the economic situation.
"Moreover, the operational disruption due to the weather at the end of the month has compounded this effect."
Routes hardest hit in terms of percentage reduction were Luton, Southampton and Glasgow, all of which experienced cutbacks in frequency and capacity over 2008, as airlines trimmed capacity with the fall-off of passenger demand.
Routes to the Northwest of England fared better than in recent months, with just a 3% decline, and the Liverpool route showed a small increase for the first time since December 2008. London routes overall were slightly up, due to a huge increase in London City passengers of 4,100.
The withdrawal of Eastern Airways from the Birmingham and Newcastle routes in late August has so far had relatively little effect upon passenger numbers, as just three days after Eastern’s last flight from the Island, Manx2 launched a replacement Newcastle service and, from the beginning of September, Flybe will be increasing its frequency of flights on the Birmingham route.
"Whilst we are disappointed to lose Eastern from the Isle of Man network, we are pleased that both Manx2 and Flybe have responded immediately to fill the gaps left," added Ann.
"The Newcastle route is important to the Island and we are very grateful to Manx2 for stepping in so quickly.
"Our route to Birmingham has consistently generated between 4,000 and 5,000 passengers per month and the additional capacity that Flybe has added means that we should be able to continue to attract these numbers."
Despite overall reductions in passenger numbers, Isle of Man routes performed relatively well in terms of the number of seats filled.
Flybe had five of its eight routes with over 60% of the capacity sold and Manx2 had four of its seven routes at over 60% load factor, with its East Midlands and Gloucester routes 70% full.
Minister of Transport David Anderson MHK remains cautiously optimistic, despite the decline: "Whilst August was not as good as we had hoped, the underlying trend still shows a gradual recovery.
"As businesses return after the summer holiday period, we are hopeful that the vital business traffic that the airlines need as the foundation for their routes will improve in September."
