Andy,<br><br>IIRC, it's about 9% at 32° F. However, once water has frozen, it is like any other solid and contracts as it gets colder - I can look up the coefficient of expansion if it's important - let me know. That contraction as temps fall is sometimes the cause of some VERY loud "BOOM!" noises on lakes when the tension from the ice contracting suddenly lets go (ice breaks).<br><br>HTH,<br><br>Tom