What is the relationship between piano pitch and season, climate and temperature? When is the right time to adjust the tune?

At least twice a year, that is, once every six months But it's best to do it once every three months.

Note that because the piano can't stand the big changes of temperature and humidity, it is heated once. Stop the heating once.

Too much, too hard, you have to fight once every two months.

If you play the piano at home, two months is enough.