def get_closest_station(latitude, longitude, minumum_recent_data=20140000, 
                        match_max=100):
    '''Query function to find the nearest weather station to a particular 
    set of coordinates. Optionally allows for a recent date by which the 
    station is required to be still active at.
    
    Parameters
    ----------
    latitude : float
        Latitude to search for nearby weather stations at, [degrees]
    longitude : float
        Longitude to search for nearby weather stations at, [degrees]
    minumum_recent_data : int, optional
        Date that the weather station is required to have more recent
        weather data than; format YYYYMMDD; set this to 0 to not restrict data
        by date.
    match_max : int, optional
        The maximum number of results in the KDTree to search for before 
        applying the filtering criteria; an internal parameter which is
        increased automatically if the default value is insufficient [-]
        
    Returns
    -------
    station : IntegratedSurfaceDatabaseStation
        Instance of IntegratedSurfaceDatabaseStation which was nearest
        to the requested coordinates and with sufficiently recent data
        available [-]
        
    Notes
    -----
    Searching for 100 stations is a reasonable choice as it takes, ~70 
    microseconds vs 50 microsecond to find only 1 station. The search does get 
    slower as more points are requested. Bad data is returned from a KDTree
    search if more points are requested than are available.
    
    Examples
    --------
    >>> get_closest_station(51.02532675, -114.049868485806, 20150000)
    <Weather station registered in the Integrated Surface Database, name CALGARY INTL CS, country CA, USAF 713930, WBAN None, coords (51.1, -114.0) Weather data from 2004 to 2017>
    '''
    # Both station strings may be important
    # Searching for 100 stations is fine, 70 microseconds vs 50 microsecond for 1
    # but there's little point for more points, it gets slower.
    # bad data is returned if k > station_count
    distances, indexes = kd_tree.query([latitude, longitude], k=min(match_max, station_count)) 
    #
    for i in indexes:
        latlon = _latlongs[i]
        enddate = stations[i].END
        # Iterate for all indexes until one is found whose date is current
        if enddate > minumum_recent_data:
            return stations[i]
    if match_max < station_count:
        return get_closest_station(latitude, longitude, minumum_recent_data=minumum_recent_data, match_max=match_max*10)
    raise Exception('Could not find a station with more recent data than '
                    'specified near the specified coordinates.')