If you have your heart set on visiting several Paris museums when you’re in town, be sure to check in advance that they’re open (or that the collection you want to see is open). There are several currently closed (or partially closed) for renovations. On the plus side, many museums also have late opening hours to help avoid the morning crowds, highly recommended, and you get to sleep in!
The Carnavalet History of Paris Museum is partially closed (most of the ground floor apartments) and there are long lines just to get the free ticket, no dates mentioned for reopening.
The Modern Art Collections (1905-1980) of the Centre Pompidou reopen May 27th (night opening at the Pompidou until 11pm on Thursdays).
The main collection of the Rodin Museum is closed through November, with just the gardens and temporary expositions open (until 8:45pm Wednesday nights).
The dome of the Pantheon is still under construction, but the building remains open (exceptionally closed mornings May 22-28 for official ceremonies).
The Louvre Pyramid entrance is open during renovations of the guest welcome area below it, although the gift shop is housed in a temporary building in the courtyard for the next two years (Louvre is open until 9:45pm Wednesday and Friday).
Victor Hugo’ House in the place des Vosges is partially closed (his living quarters) until June 2nd.
And if you’re heading out to Disneyland (hey, don’t judge!), Space Mountain is closed for renovations through the end of July).
For other evening cultural excursions, the Grand Palais expositions (including the wildly popular Vélazquez retrospective) are now open until 10pm Wednesday-Saturday. Notre Dame Cathedral is open weekend evenings in May and June at 9:15pm for a special audiovisual show with music (free entry).
Also, be aware that because of additional Vigipirate (anti-terrorist) security checks, lines in some places will be longer than usual, including Notre Dame and Sainte Chapelle, even if you have a Museum Pass.