def dew_point(t, h):
    """Calculate dewpoint

    Args:
        t (float): temperature in °C
        h (float): relative humidity in %

    Returns:
        calculated dewpoint in °C

    Ref:
        https://www.ajdesigner.com/phphumidity/dewpoint_equation_dewpoint_temperature.php
    """
    return round((h / 100) ** (1 / 8) * (112 + 0.9 * t) + 0.1 * t - 112, 2)