def add_lat_lon(df):
    """Add lat and lon columns to dataframe in WGS84 coordinates

    Parameters
    ----------
    df : GeoDataFrame

    Returns
    -------
    GeoDataFrame with lat, lon columns added
    """
    geo = df[["geometry"]].to_crs(epsg=4326)
    geo["lat"] = geo.geometry.y.astype("float32")
    geo["lon"] = geo.geometry.x.astype("float32")
    return df.join(geo[["lat", "lon"]])