def cull_dataset(coords):
    """
    As we currently have a limited number of API calls(60) every minute with the
        current Weather API, we must shrink the dataset significantly. As the
        OpenWeatherAPI models have a resolution of between 2.5 - 70 km, we will
        go for a resolution of 25km. Assuming we travel at 100km/h for 12 hours,
        1200 kilometres/25 = 48 API calls

    As the Google Maps API has a resolution of around 40m between points,
        we must cull at 625:1 (because 25,000m / 40m = 625)
    """

    return coords[::625]