Indoors Weather

NASA has a building that’s large enough to have it’s own weather.

The Vehicle Assembly Building¹, with it’s 160m of vertical open space and 32000 m² of floor area, is used to assemble vehicles (duh!). Specifically, it’s where Space Shuttles and the Saturn V are being built.

Depending on the weather outside, it’s possible for humidity to condense into clouds inside the building, leading to rain.
That’s not an intentional “let’s use this as a weather-simulator” kind of deal. The building actually has extremely powerful air condition to avoid that issue.

It’s simply a sufficiently large enclosed space to produce actual, natural, weather effects. Awesome!