Spring 2011 was the third combined windiest and driest on record in the Valley, according to the National Weather Service.
The average wind speed at Phoenix Sky Harbor International Airport during spring 2011, defined as April and May, was 8 mph. This was the 11th windiest spring on record and the windiest spring since 1983.
The average relative humidity, a measure of the moisture capacity the atmosphere has, during spring 2011 was 18.6 percent making it the sixth lowest/driest on record.
When combining the average wind speed and average relative humidity into a single measurement, spring 2011 ranks as the third windiest and driest combined on record. The windiest-driest was 1974 and the least windy/wettest was 1941.