In Japan, rainy season is recognize in June(we call it “Tsuyu”) and hot summer season is coming.
I(Morita) used to live in States, LA and it temperature was pretty similar.
But I personally feels Japan summer season is more hot than LA.
Biggest difference may be humidity.
This humidity gives much stress and sweat if its in high condition.
Also, this humidity often gives damages inside room(ex. mold).
During our work, we often face very hot room because the room we going to visit basically becomes closed room.
To avoid this humid damage, we often advice to increase frequency of ventilation.
Especially if its an apartment, building is basically made out by concrete and concrete will close the air and obstruct the movement of air and this induce the mold.
Therefore, try give space to ventilate the air becomes very important to have comfortable living.
I think everyone have their own way or idea to get over this hot weather.
Please have a joyful summer day!