Squam Lakes Science Center is doing some fun things on their Facebook page (Guess the animal, storytimes, activities, etc.): https://www.facebook.com/nhwildlife/
McAuliffe-Shepard Discovery Center has an almost daily blog with fun STEM activities: https://www.starhop.com/blog
SEE Science Center has some great videos showing science experiments that can be done from home: https://see-sciencecenter.org/