Why is winter the flu season?

Scientists had long theorized that it was mostly because colder weather kept people indoors, where the close contact was more likely to spread the virus. But a new analysis puts the blame on the amount of humidity in the air. Looking at previous studies, climate physicist Jeffrey Shaman of Oregon State University found strong evidence that flu transmission peaks when absolute humiditythe pure percentage of water in the airis lowest, during cold, dry winter days. The correlations were surprisingly strong, Shaman tells the Associated Press. The virus ability to survive and be transmitted person-to-person is greatly affected by how dry or wet the air is. To humidify your air at home and help ward off flu, you can buy a humidifier, or try Grandmas low-tech trick: Allow a teakettle to boil on the stove for a while.  more