Debbycake,
Depending on the severity of the rain and weather conditions, some excursions may be canelled (particularly if they involve any time in the air or on the water). There are some that go no matter what the weather. It really depends on how predominately good weather conditions factor into the experience as to folks cancelling or just "going for it". You might want to check out our sister site, Port Reviews for a number of suggested excusions at each of your ports:
www.alaskaportreviews.com .
Nancy