Siberian High

The Siberian High (also Ruso-Siberian High/Anticyclone) is a massive collection of cold or very cold dry air that accumulates on the Eurasian terrain for much of the year. It reaches its greatest size and strength in the winter, when the air temperature near the center of the high-pressure cell or anticyclone is often lower than −40 °C (−40 °F). The sea-level pressure (atmospheric pressure) is often above 1,040 millibars (31 inches of mercury). The Siberian High is the strongest semipermanent high in the northern hemisphere and is responsible for both the lowest temperature in the Northern Hemisphere, of −67.8 °C (−90.0 °F) on January 15, 1885 at Verkhoyansk and the highest pressure, 1083.8 mbar (108.38 kPa, 32.01 inHg) at Agata, Siberia on December 31, 1968.^[1]

The Siberian High affects the weather patterns in the higher latitudes of the Northern Hemisphere, as far as the Po Valley in Italy. It may block or reduce the size of low-pressure cells or cyclones and generate dry weather across much of the Eurasian and Canadian landscape. The Siberian High is responsible both for severe winter cold and attendant dry conditions across most of Siberia. During the summer, the Siberian High is largely replaced by a low-pressure system, resulting in a summer precipitation maximum across almost all of Siberia. In general, the Siberian High pressure system begins to build up at the end of August, reaches its peak in the winter, and remains strong until the end of April.