School snow shutdowns: D.C. area versus the rest of the country

Reddit poster atrubetskoy has developed a map “How much snow it typically takes to cancel school in the U.S.”.  In the D.C. area, the map suggests it takes about 1-3 inches – which seems more or less right to me.

How much snow it typically takes to cancel school in the U.S. - click to enlarge (atrubetskoy <a href="http://www.reddit.com/r/MapPorn/comments/1wiacl/how_much_snow_it_typically_takes_to_cancel_school/">via Reddit</a>)

How much snow it typically takes to cancel school in the U.S. – click to enlarge (atrubetskoy via Reddit)

Examining the map in its entirety, it appears about half the country cancels schools for more snow and half for less snow than D.C.  In much of the South and along the West Coast, it just takes an inch or less – or even the mere mention of snow – to close schools, according to the map.  The Northeast, Great Lakes, northern Plains and northern Rockies generally require 6 inches or more.

Maybe we’re not such weather wimps after all?

Atrubetskoy, the map maker, added these notes about the map and its assumptions:

  1. The lightest green says “any snow” but also includes merely the prediction of snow. Also, this is snow accumulation over 24 hours/overnight.
  2. In much of the Midwest and Great Plains, school closing often depends more on wind chill and temperature than on snow accumulation (“cold days”). Thus, this map may be misleading in those areas.
  3. Many jurisdictions in California and other western states have significantly varied snowfall, depending on elevation. This makes it difficult to find an “average” number, or often makes it misleading.
  4. Urban areas like Chicago and New York have more resources to clear snow and often need more to cause closings.
  5. To everyone saying “I grew up in so-and-so and we never closed school,” policies have changed in the last 20 years to make closing a much more common occurrence. Just because schools stayed open back then doesn’t mean they do these days.
  6. Hawaii does get snow! Just… not where people live.
  7. Data was taken from hundreds of various points from user responses and interpolated using NOAA’s average annual snowfall days map. Any corrections/additions are welcome, just give a decently specific location.

What do you make of this map? Is it consistent with your experience?

Related: Time for Fairfax County to toughen up | Counterpoint: Fairfax County’s defense for shutting down

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