If the Irish and Dutch decided not to go out on a rainy day, the whole country would cease to function. It doesn't seem to make a bit of difference in my neck of the woods.
And I was just going to mention that...In places like London where (according to folk) its rainy and foggy day in, day out then it must not affect much? And on the islands like Dominican Republic its considered quite sexy to do it during the rain.
However, back in the winter...I did find that cold, dreary and foggy days tended to bring about some interest (and very bad for driving!) but when it would ice over or the winds pick up it was silent. At my 'other' job, customers hardly wanted to even be on the phone during the thunderstorn!