Is bubble water useless in hot weather?

No, although it is not easy to form bubbles in hot and dry weather, it does not mean that bubble water cannot be used in hot weather.

Bubbles are formed due to the surface tension of water. When the attraction between water molecules is greater than the attraction between water and air, bubbles tend to form. In hot and dry weather, due to the low air humidity, the attraction between water and air is relatively small, so bubbles are not easily formed. However, if the surface tension of the water is greater than the attractive force of the air, bubbles can still form.

Therefore, in hot weather, as long as the surface tension of water is greater than the attraction of air, you can still use bubble water.