Door sure looks like someone has smacked it a bunch times by the top hinge! Here are couple of things to look for that might provide more info on what is going on: 1.) bottom hinge is set deeper into the jamb than top hinge and could be shimmed out to hang the door straighter . (Can’t tell as the side gap isn’t shown in pics that I could see. ) 2.) as mentioned above, top hinge needs to be set deeper into jamb with a longer screw. (Gaps look uniform here so unlikely but worth a look) 3.) Measure corner to corner on each side to see if someone has cut door with a taper to suit a settled home . Measure jamb as well and measure diagonally to see if it is square. It could help explain why the gaps aren’t uniform and show that it’s been a problem for sometime.
4.) check any windows in same wall by measuring corner to corner for squareness and /or difficulty in opening and closing. Any drywall/plaster cracks? Stucco cracking on outside of home or gaps in siding? Cracks in foundation?This would be indicative of a settling home.
5.) Is there a basement or crawlspace? Look for any water intrusion or bugs that could be affecting the structure causing it to deflect in that area. Same goes for the wall framing as it’s an exterior wall.
6.) as mentioned above by someone else, humidity can affect wood with expansion and contraction, but it is mainly uniform and unlikely to affect one area of the door more than another. It could make a tight jamb/poorly hung door snug to open and close in the winter as the jamb contracts.
I hope you find it’s an easy fix as they often are.