def set_contourf_properties(stroke_width, fcolor, fill_opacity, level, unit):
    """Set property values for Polygon."""
    return {
        "stroke": fcolor,
        "stroke-width": stroke_width,
        "stroke-opacity": 1,
        "fill": fcolor,
        "fill-opacity": fill_opacity,
        "title": "{} {}".format(level, unit)
    }