def rateTCan24(params: dict, states: dict) -> float:
    """
    Summary

    Parameters
    ----------
    params : dict
        tau: float
            Time constant of the process.
        k: float
            Gain of the process.

    states : dict
        TCan: float
            TCan is the simulated or measured canopy temperature. [oC]
        TCan24: float
            The 24 hour mean canopy temperature [oC s-1]

    Returns
    -------
    float
        24 h mean canopy temperature, approximated by
        a ﬁrst order differential equation. [oC s-1]
    """

    tCan24_ = (1/params["tau"])*(params["k"]*states["TCan"] - states["TCan24"])

    return tCan24_