Winter storms are historically very expensive and are the third-largest cause of catastrophe losses, behind only hurricanes and tornadoes.

According to Dr. Robert Hartwig, president of the Insurance Information Institute, “Severe winter storms are often the third-largest cause of insured catastrophe losses in any given year—after hurricanes and tornadoes.”
  
“Winter storms accounted for 7.1 percent of all insured catastrophe losses between 1993 and 2012, placing it third behind hurricanes and tropical storms (40 percent) and tornadoes (36 percent) as the costliest natural disasters,” added Hartwig.
 
On an inflation-adjusted basis, insurers paid $27.8 billion in winter storm claims to policyholders over this period—or $1.4 billion per year, on average, according to Property Claims Service for Verisk Insurance Solutions.
 
The I.I.I. offers additional facts, suggestions and statistics on winter storms here.