In this article we examine volatility measures and investigate what factors explain price volatility in different US domestic air routes. We find that volatility remains reasonably stable up to 2 weeks prior to the flight, at which point it increases significantly. The type, LCC or legacy carrier, and identity of the airlines appears to have a major impact on the volatility measures, and that these effects are different for 2 weeks out and 1 day out, even after controlling for market differences.