A recent study aimed to determine the relationship between ambient humidity and viability of the influenza A virus found that viability during transmission through the air was highest at lower humidity (<50% RH) or at ~100% RH (i.e. large droplets that settle out of the air and survive on a surface to infect via contact transmission).
Check out in particular the section:
Implications for Influenza’s Transmission Patterns
plosone.org/article/info%3A...
(Free Access)
It is rather sobering to discover that our ideas on how influenza spreads come from 60 to 80 years ago. We still have so much to learn.
So.... Regularly wash your hands!!