The restoration began in January 1998 when the monument was closed so that heating and air-conditioning systems could be upgraded. The elevator, which dates from 1959, also was modernized. That project alone cost $1.9 million.

Yes, the Washington Monument is air-conditioned inside for the comfort of visitors and the preservation of the structure. The 555-foot obelisk features a modern elevator that takes guests to the observation deck in about 70 seconds. The observation deck, which offers eight viewing windows across the four cardinal directions, is climate-controlled to mitigate the intense summer heat and humidity common in D.C. In 2026, the National Park Service emphasizes that while the monument provides a cool escape, visitors must still secure timed-entry passes in advance, as they are free but disappear very quickly during the peak summer months. It is important to note that the monument's interior was not always climate-controlled; the current HVAC systems were part of major renovations designed to handle the thousands of guests who visit daily. For those who choose to take the 897 steps (rarely allowed except for special tours), the air conditioning is a welcome necessity to maintain air quality and temperature throughout the narrow interior.