Format observations sent by IBM.
format_wu(raw, raw_tz = "UTC", raw_temp_unit = "F", raw_crs = 4326)
a data.frame, data.table, sf or sftime with the raw observations and columns "obsTimeUtc", "lat", "lon", "tempAvg"
the initial timezone, see PurpleAir API documentation
the initial temperature unit
the initial coordinate reference system
sftime from hourly_temp class