Indoor rain day
Deep on Shanghai Museum or Urban Planning at the square — or 1933 spiral ramps in Hongkou. Mall day: Kerry or Grand Gateway, one only. Science / natural history museums are family rain backups — do not also stack a Bund concrete marathon.
Wet nights and hard wind
Hard slanting rain on the Bund: watch lights from a Lujiazui mall window, or just hotel. Cruises follow typhoon / wind notices that day. Concession plane-tree streets get slick — shift to Sinan / Xintiandi arcades.