If you built a snowman during the day the snow only needs to be below freezing. It can get colder that night or the next day by quite a bit. The exterior of the snowman would be colder than the inside even though they’re both frozen.
If you built a snowman during the day the snow only needs to be below freezing. It can get colder that night or the next day by quite a bit. The exterior of the snowman would be colder than the inside even though they’re both frozen.
Ice also has a fairly high specific heat capacity, which means that changing the temperature means there’s lots of energy involved. Energy can’t just leave the ice at whatever rate you want, which means there’s a potential bottleneck.
As the environment cools down during a clear skies, there a lot of energy trapped inside the snow, and it’s leaving at some slow pace. Even when there’s less heat in the snow, that change translates to a very small difference in temperature. The air around it can also cool down much faster, which means that the temperature difference can be surprisingly big.