WeatherBill (www.weatherbill.com) published the first study identifying the relationship between weather conditions and flight disruptions (both cancellations and delays) in the United States. The study quantifies the impact of temperature and precipitation on major airports and airlines and defines delay times by "minutes per inch of rain" and "minutes per degree of temperature deviation" at each major airport and airline.

Almost 14% of the near 21 million flights evaluated in the study were delayed or canceled due to weather -- the leading cause of flight disruptions. This study, the first of its kind, demonstrates the extreme sensitivity of major airports and airlines to slight deviations in rainfall or temperature. Such delays can have a crippling impact on US transportation and the economy as a whole.

"This is an industry based on schedules. Weather disruptions increase the operational costs of airlines and negatively affect customer relationships," said David Friedberg, CEO of WeatherBill. "We can't control the weather but now we can do a better job understanding the relationship between weather and flight delays. WeatherBill also provides weather contracts that can protect airline profits from the impact of adverse weather."

More than 25% of all flights studied were canceled or delayed. Over 55% of those disruptions (3 million flights) were weather-related. The study estimates the sensitivity of major airports and airlines to adverse weather; facilitating statistically reliable estimates of future flight delays. A free copy of the complete study and summary can be downloaded at http://www.weatherbill.com/learn/research.

Weather disruptions vary by season, with the highest frequency in winter months (16%) followed by summer (15%), spring (13%), and fall (12%). Delays are more sensitive to precipitation than temperature (although the study notes that warmer temperatures reduce winter delays and increase summer delays).

Rain-related flight delay times range substantially across the 54 airports studied. During spring months, Atlanta suffers 29 delay minutes per inch of rain and San Francisco averages 41 delay minutes per inch of rain. Chicago's O'Hare is one of the top five most rain-delayed airports year-round for arrivals, ranging from 75 delay minutes in the winter to 37 delay minutes per inch of rain in the summer. Reno can expect 54 delay minutes in the spring while Phoenix averages 14 delay minutes per inch of rain. Phoenix is in the top five most rain-delayed airports for departures in the spring, summer and fall.

Rain-based delay averages for the 16 larger airlines studied are based on inches of rainfall above normal. AirTran, Comair, Expressjet, and Skywest can all experience 15 delay minutes per inch of rain above normal, during the spring. Expressjet is one of the top five most rain-sensitive airlines every season for arrivals; ranging from 13 minutes in the winter to 11 minutes per inch of rain in the summer. When it comes to departures, Skywest and Comair are in the top five most rain-sensitive airlines every season.

WeatherBill, Inc. (www.weatherbill.com) provides the only online service that allows businesses to protect revenue and control costs from the impact of bad weather. Founded by CEO David Friedberg and CTO Siraj Khaliq, former members of the Google team, WeatherBill is funded by New Enterprise Associates, Index Ventures, and Allen & Company and is backed by Nephila Capital, one of the world's largest weather risk and catastrophe reinsurance fund managers.

Source: WeatherBill

Web site: http://www.weatherbill.com/