SEATTLE — When it officially opens in December, the Hyatt Regency at Eighth Avenue and Howell Street will be both the largest hotel in Washington state and among the most closely watched.

With its 1,260 rooms, conference facilities, and proximity to the planned expansion of the Washington State Convention Center, the Hyatt is key to Seattle’s ambitions to play in the big leagues of the convention business and bid for massive corporate events only a handful of American cities can currently handle.

But the property is opening just as the Seattle area’s hotel market — one of the hottest in the country — is cooling under a crowd of new entrants, from “limited-service” hotels to upscale boutiques and “lifestyle” properties such as the Marriott-owned Moxy in South Lake Union.

By the time the Hyatt opens, Seattle’s downtown hotel market will have grown by a stunning 2,550 rooms since January 2017, or more than five times the number of rooms the city added in the two previous years, according to Visit Seattle, which markets the city’s hospitality and tourism sectors. Regionwide, there are roughly 65 new or underdevelopment hotels across King, Snohomish and Pierce counties, according to CBRE, a real estate investment firm.

No one is forecasting a repeat of the Great Recession, when an imploding travel industry led desperate Seattle hoteliers to cut room rates by 13 to 15 percent, a strategy known as “slash and burn.”

Hotel demand in Seattle remains strong, thanks to robust growth in tourism and business travel. That’s one reason room rates are still rising, though not quite as fast as before. A room in downtown Seattle averages $229, up 3 percent from 2017.