Soap bubbles blown into air that is below a temperature of −15 C (5 F) will freeze when they touch a surface. The air inside will gradually diffuse out, causing the bubble to crumple under its own weight.
At temperatures below about −25 °C (−13 °F), bubbles will freeze in the air and may shatter when hitting the ground. When, at this low temperature, a bubble is blown with warm breath, the bubble will freeze to an almost perfect sphere at first, but when the warm air cools and thus is reduced in volume there will be a partial collapse of the bubble. A bubble, blown successfully at this low temperature, will always be rather small in size: it will freeze quickly and continuing to blow will shatter the bubble.
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