A320 pilot reported the loss of the hydraulic system after departure and return to departure airport. The flight crew was assigned a different aircraft and departed; but had to divert when destination airport weather deteriorated below minimums.

Narrative

Scheduled flight was ZZZ-ZZZ1 leaving at XA05L. Flight departed early; made it as far North as abeam Location A; then elected to air return to ZZZ due to a loss of all or nearly all hydraulic fluid. Decision to air return was largely based on the extremely low visibility in and around our ZZZ2 metro destination and the loss of a CAT3 dual ILS capability. The decision was made in collaboration with Dispatch and ops via SATCOM. We returned to ZZZ at XB30L; did a tail swap from Aircraft X to Aircraft Y; then departed ZZZ again at XC40L. We were 10 minutes from landing in ZZZ1 at XD00L when ZZZ1 closed their Tower operations per their normal schedule. ZZZ1 was reporting VV001 and 1/4 mile visibility with 2200-3000 RVR. Since the Tower had closed the ILS XX CAT2 into ZZZ1 it became illegal and; since we didn't have the 200-1/2 minimums (specifically the ceiling minimums) for an ILS XX CAT1; we diverted to ZZZ3. Although ZZZ4 was our listed alternate; the pre decision made in coordination with Dispatch as we approached ZZZ1 was to first try to divert to ZZZ3 (if feasible) should ZZZ1 weather be illegal.