Well at least they gave us some lead time.
The First Presidency of The Church of Jesus Christ of Latter-day Saints has announced the long-term closure of the Oakland California and Washington, DC Temples for extensive renovations. The Oakland California Temple will close in February 2018 and the DC Temple will shut its doors in March of the same year.
According to the Mormon Newsroom, the nature of the renovations includes full upgrades to mechanical systems as well as a refresh of furniture and furnishings.
Given the depth of the renovations, the temples will be closed for much longer than is typical. Work at the Oakland California Temple is estimated to be completed in 2019. DC will reportedly follow in 2020. Because of the length of the closures, the temples will be rededicated and also hold public opens houses prior to the rededications. No word on whether the oft-loved cultural celebrations will also accompany the rededications, but we can only hope for rousing song and dance numbers about startup venture capitalism and lobbying.
Latter-day Saints living in the Oakland district will be able to travel to Sacramento (or if they are really bored – Fresno) to participate in temple work. Washington DC patrons in the immediate area will presumably be encouraged to visit the newly dedicated Philadelphia Pennsylvania Temple a few hours up Interstate 95. Others might need to venture to Raleigh, North Carolina or Columbus, Ohio. (Yes, Pittsburgh is in the DC district for some reason.)
Long-term closures of this nature are not unheard of, so this does not mean anything is inherently flawed in the buildings (except for the closure of the poorly constructed Montreal Quebec Temple—sorry Quebecois). Like any building, even a House of the Lord is subject to the stresses of age. Both temples date from the 60s, although they were dedicated 10 years apart.