An interesting corollary to your observation which I have noticed is that the climate in which a stringed, and especially, a bowed, instrument is built often corresponds to the climate in which that instrument sounds best. This isn't surprising, since an instrument is typically fine-tuned by its builder to sound its best when - and where - it's built, and it would follow that it would likely sound best when played in similar climatic conditions, especially in regards to humidity. However, I rarely, if ever, see this discussed in print.