Do icicles melt from the inside or from the outside?

Answer 1

Well icicles would melt from the outside, because the inside is exposed to ice, while the outside can be exposed to the air....

However.....when ice is formed it traps air, so as it melts you might see a hole in the middle, but it is not from melting as such.

In addition that air hold could let in more warmer air, potentially allowing the ice to melt from the inside...

But an icicle is normally formed by dripping water, so the air bubbles will only be very small.

Answer 2

They melt from the outside.

The outside temperature would affect the outside surface of the icicle, while the inside of the icicle is relatively insulated from the outside's warmth.

The heat gradient of an icicle on a warming day would have the warmest part of the icicle at the outside surface, with the coldest part at the icicle's core.

Answer 3

Just think about it.

If it thawed from the inside out, it would not drip at all and suddenly, as the water broke through the last layer of ice, the whole icicle would turn to water. Is this consistant with observation? NO.

Icicle, when they thaw, drip drip drip constantly until they disappear, which indicates they thaw from the outside.

Answer 4

From the outside. The surface that is exposed to warmer air will gain heat first.