シベリア連邦管区
The Siberian orange snow of 2007 was an anomalous phenomenon that occurred in early February 2007. Beginning on 31 January 2007, an orange-tinted snow fell across an area of in Omsk Oblast, Siberian Federal District, Russia, approximately from Moscow, as well as into the neighboring Tomsk and Tyumen Oblasts. It was unclear what caused the orange snow. Speculation ranged from pollutants to a storm in neighboring Kazakhstan.