[fersho311]

I read the whole article and couldn’t understand how or why this happens. Is the reason behind this unknown?

[mmerlin]

My high school chemistry teacher simplified it down to the greater "rate of change" of temperature dropping, for the hot water, causes it to end up freezing faster than the cold water.

[ntsplnkv2]

The rate of change would slow down as it approached the colder temperature though, would it not?

[GreeniFi]

The best explanation I got was that covalent bonds are weaker in hot water than cold.

[mensetmanusman]

It’s apparently not true for very pure water.