Specifically, most functions in this package interact with
the National Climatic Data Center application programming
interface (API) at
http://www.ncdc.noaa.gov/cdo-web/webservices/v2.An access token, or API key, is required to use this R
package. The key is required by NOAA, not the creators of
this R package. Go to the link given above to get an API
key.