The number of visitors to Hawaii fell in September for the first time in two years as fewer travelers arrived from the western U.S., the state’s tourism agency said Thursday.

Nearly 595,000 travelers visited Hawaii, down 1 percent from the same month last year. Spending sank nearly 5 percent to $1 billion.

The last time visitor arrivals declined was in August 2011, when they fell 4.2 percent from a year earlier.

The Hawaii Tourism Authority has been warning growth will slow, particularly compared to last year, when 10 percent more travelers came to the islands.

Vice President David Uchiyama told industry representatives in August that growth would continue but a slower pace as airlines cut seats and flights serving Hawaii from the U.S. mainland.

He noted airlines were scaling back recently added flights from West Coast cities like Oakland, San Jose and San Diego. Airlines have also reduced the frequency of newly launched direct service between Honolulu and New York and Washington, D.C., because of weak demand.

Travelers from the western U.S. fell 5.9 percent in September compared to a year earlier.

International travelers from places like Japan and China are countering some of the domestic slowdown, however, as airlines increase the number of seats on flights to Hawaii from Japan and add direct flights from China.

Japanese arrivals rose 2 percent, but most of those who came stayed for a shorter period. This led spending to plunge almost 15 percent.

For the first nine months of the year, 4.5 percent more visitors came to Hawaii than in the same period of 2012, and spending rose 4 percent.

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Photo Credit: The Hawaii Kai Marina with the Koko Crater in the background. Bert Kimura / Flickr