A wave of frigid air spilled down over Europe and Russia from the Arctic in mid-December, creating a deadly cold snap. According to BBC.com, at least 90 people had died in Europe, including 79 people, mostly homeless, in Poland. In places, the bitter cold was accompanied by heavy snow, which halted rail and air traffic for several days during the week of Christmas.
This image shows the impact of the cold snap on land surface temperatures across the region from December 11–18, 2009, compared to the 2000–2008 average. The measurements were made by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Places where temperatures were up to 20 degrees Celsius below average are blue, locations where temperatures were average are cream-colored, and places where temperatures were above average are red. Light gray patches show where clouds were so persistent during the week that MODIS could not make measurements of the land surface temperature. The biggest anomalies were in northern Russia, but a swath of below-average temperatures stretched across the countries around the Baltic Sea as well.
Northern Hemisphere winter 2009–2010 temperatures were unusually cold across much of the United States, Canada, and Europe compared to previous winters this decade, while Greenland, North Africa, and the Middle East were warmer than usual.