coverage will be excluded from the county average.
filter_hourly(fips, hourly_data, coverage = NULL)df element from an
isd_monitors_data call.df and stations. df is
a dataframe of hourly weather data filtered based on the specfified
coverage, as well as columns ("var"_reporting) for each weather
variable showing the number of stations contributing to the average for that
variable for each hour. The second element, stations, is a dataframe
giving statistical information for stations that meet the specified coverage
requirements. The column station gives the station id (USAF and
WBAN identification numbers pasted together, separated by "-"). Note: One
of these identification ids is sometimes missing. For example, a value in
station might be 722029-NA. The column var
gives the weather variable associated with the row of statistical values
for each station and variable combination. calc_coverage gives the
percentage coverage for each station-weather variable combination. These
values will all be greater than or equal to the specified coverage
value. standard_dev gives the standard deviation of values for each
station-weather variable combination. max and min give the
minimum and maximum values, and range gives the range of values in
each station-weather variable combination. These last four statistical
calculations (standard_dev, max, min, and
range) are only included for the seven core hourly weather variables,
which include "wind_direction", "wind_speed",
"ceiling_height", "visibility_distance", "temperature",
"temperature_dewpoint", and "air_pressure". (The values of
these columns are set to NA for other variables, such as quality
flag data.)