def METHOD_NAME(flow_df: pd.DataFrame, precip_df: pd.DataFrame):
    tz = pytz.timezone("UTC")
    precip_df["hour_updated"] = precip_df["hour_updated"].map(
        lambda x: datetime.strptime(x, "%Y-%m-%d %H:%M:%S")
    )
    precip_df["hour_updated"] = precip_df["hour_updated"].map(
        lambda x: tz.localize(x)
    )
    joined_df = precip_df.merge(
        flow_df, left_on="hour_updated", right_on="datetime", how="outer"
    )[4:-4]
    nan_precip = sum(pd.isnull(joined_df["p01m"]))
    nan_flow = sum(pd.isnull(joined_df["cfs"]))
    return joined_df, nan_flow, nan_precip