The Severe Winter of 2008-09 in Illinois

The winter of 2008-2009 in Illinois had 12 severe winter storms and many days with extremely low temperatures. Normally, the state has five severe storms in a winter. In northern Illinois the December-January period was among the state’s ten coldest and snowiest winter periods on record. The climate winter, December-February, had a mean temperature that was 2.5° F below normal, and was the fifth coldest since 1890. The period of 2006-2009 is the second time since 1900 that Illinois has had three consecutive severe winters. The first trio of bad winters came during the 1976-1979 period. The 2008-2009 winter snowfall values ranged from 50 inches in the extreme north to less than 5 inches in southern Illinois. Snow amounts in the northern sections ranged from 10 to 25 inches above normal, but snowfall totals in central Illinois were near normal and those in the south were below normal. In December 2008, seven winter storms occurred. Temperatures across Illinois were 3.5° F below normal and snowfall exceeded 20 inches. Four storms had heavy snows and freezing rain. The January average temperature statewide was 4.6° F below normal and snow was above normal across Illinois, with record low daily temperatures in mid-month and four winter storms. February had normal temperatures and no snowstorms, but two heavy rainstorms occurred. March began with severe storms producing tornadoes, but ended with a sizable snowstorm. Atmospheric conditions over the U.S. during December and January were unstable and very active. These conditions resulted in numerous low-pressure centers that developed over the Rockies and then moved east across or near Illinois, causing several winter storms. As the synoptic-scale flow field over the U.S. became more zonal late in the season, the number of cyclones affecting Illinois decreased. The large number of storms and extremely low temperatures for two months resulted in major negative impacts in four sectors. Property damages totaled 672 million dollars, and all forms of transportation in Illinois suffered major problems and losses. Power systems were badly damaged with major outages producing losses and costs of $512. The storms also created many state and local government responses that cost 510 million dollars. The winter also affected human health and welfare with 16 persons killed and thousands injured. Damage to the environment included excessive flooding. Many winter conditions also impacted agricultural activities and retail business, in which reductions in sales totaled 292 million dollars.