Sion Airport PC-6, Pilatus PC-7, Pilatus PC-9 and Pilatus PC-21 as well as helicopters it uses Sion intensively with the fighter jets F/A-18 and F-5 Tiger. It is the home base of the militia pilot unit Fliegerstaffel 19 Swans with F-5E. Sion Airport is, at both ends of the runway, equipped with retractable arresting gear devices (used by the F/A-18 and in case of a problem by the F-5). Because of the redimension of the Swiss Air Force it is planned that the Air Force will leave Sion after 2017 and Sion will be used by civil aviation only, acting only as
Sion District the question. Sion town has an average of 82.6 days of rain or snow per year and on average receives of precipitation. The wettest month is December during which time Sion receives an average of of rain or snow. During this month there is precipitation for an average of 7.4 days. The month with the most days of precipitation is August, with an average of 8.2, but with only of rain or snow. The driest month of the year is April with an average of of precipitation over 5.9 days. In Sion about 11,917 or (32.2%) of the population have