Modern studies using freezers with well-understood properties have observed the Mpemba effect where water supercools before freezing. Water that starts out cooler tends to reach a lower supercooled temperature before freezing.

Also from the Wikipedia article.

If you define the Mpemba effect as hot water reaching 0 degrees faster, then no, it's not observable. But if you define the Mpemba effect as heated water freezing sooner, (remembering that freezing can initiate below the "freezing point" when water is subcooled) then the Mpemba effect may be observed.

If true, it would be interesting that cool water is less likely to nucleate and form ice than water that was heated.