The National Weather Service maintains a Cooperative Observer Network consisting primarily of volunteers that record observations of precipitation and high and low temperatures each day. There is at least one location in each of the 40 counties in the Blacksburg County Warning Area. The map below shows an analysis of the snowfall for the 2004/2005 winter season across the Blacksburg County Warning Area, based on those Cooperative observing sites that report snowfall. The second map shows the average winter season snowfall across the Blacksburg County Warning Area based on the individual average of the periods of record at each Cooperative observing site. Periods of record vary from 10 to more than 60 years. For details about the individual sites and their snowfall records, click here for a table listing 2004/05 snowfall and snowfall averages by month. Finally, it is worth noting that the snowfall average map includes the entire period of record for each of the sites listed, but should not be confused with climate normals, which are an average during a moving 30 year window. The latest climate normals generated by the National Climatic Data Center in Asheville would cover the period from 1971 to 2000. The normals could be markedly different from the averages listed below, especially since the decade of the 1960s had unusually heavy snow across much of the area.