This function returns a tibble (dataframe) with a weather
station on each row with the following columns:
id: The weather station's ID number. The first two letters
denote the country (using FIPS country codes).
latitude: The station's latitude, in decimal degrees.
Southern latitudes will be negative.
longitude: The station's longitude, in decimal degrees.
Western longitudes will be negative.
elevation: The station's elevation, in meters.
name: The station's name.
gsn_flag: "GSN" if the monitor belongs to the GCOS Surface
Network (GSN). Otherwise either blank or missing.
wmo_id: If the station has a WMO number, this column gives
that number. Otherwise either blank or missing.
element: A weather variable recorded at some point during
that station's history. See the link below in "References" for definitions
of the abbreviations used for this variable.
first_year: The first year of data available at that station
for that weather element.
last_year: The last year of data available at that station
for that weather element.
If a weather station has data on more than one weather variable, it will
be represented in multiple rows of this output dataframe.