i need some ideas, however i must note the main aspect of gameplay will not be the disasters, and instead, something similar to FNAF.

(Be sure to make it abide to the CG :D)

Maybe acid rain or earthquakes? Drought?

This is technically not a natural ‘disaster’, but maybe add a power-outage/lightning-storm

yea the power outage is technically going to be based on player's camera system and door usage but nontheless, great ideas!