How to convert UTM coordinates to lat/long values

Use PostGIS to convert coordinates from UTM to latitude and longitude.

In order to convert UTM X/Y values into latitude/longitude coordinates, you will need to know the SRID (Spatial Reference System Identifier) of your dataset. Use the SRID as an argument within a combination of several PostGIS functions (ST_Transform, ST_SetSRID and ST_MakePoint) as shown in the following query, where the SRID of our dataset is 25831:

UPDATE table_name
   SET the_geom =
            ST_Transform(
                ST_SetSRID(
                    ST_MakePoint(x, y),
                    25831
                ),
                4326
            )