United Airlines offers must-book-now Hawaii roundtrip airfare deals to four islands

United Airlines is offering discounted roundtrip airfares for early 2010 travel to Oahu, Maui, Kauai and the Big Island from a handful of Mainland U.S. cities the carrier serves.

The rates—part of a promo deal United is calling the “Hawaii Fun in the Sun Sale”—are good for travel from Jan. 12, 2010, to March 4, 2010—coinciding with Hawaii’s busy winter travel season.

The catch? Tickets must be purchased on or before Dec. 15th. That’s right, folks—by tomorrow!

A bit of advice. We’ve found cheaper winter season roundtrip fares to the Islands on Hawaiian Airlines for departures from Los Angeles and San Francisco, than United’s “Fun in the Sun” deal had listed. Still, United’s sale fares for direct flights from Denver and Chicago seemed good deals to us.

Here is United’s “Hawaii Fun in the Sun Sale” each-way fare breakdown; a roundtrip purchase is required to get the fare:

Oahu:

Honolulu – San Francisco, Calif.: $257
Honolulu – Los Angeles, Calif.: $261
Honolulu – Denver, Colo.: $281
Honolulu – Chicago, Ill.: $298

Big Island of Hawaii:

Kona – San Francisco, Calif.: $265
Kona – Los Angeles, Calif.: $269    
Kona – Denver, Colo.: $289
Kona – Chicago, Ill.: $306
    
Maui:

Kahului – San Francisco, Calif.: $261
Kahului – Los Angeles, Calif.: $265
Kahului – Denver, Colo.: $285
Kahului – Chicago, Ill.: $302         

Kauai:

Lihue – San Francisco, Calif.: $265
Lihue – Los Angeles, Calif.: $269        
       

For more information on United’s “Hawaii Fun in the Sun Sale” or to book a flight as part of the deal, click here.