The Water Anomaly

Water is absurdly good at absorbing heat without changing temperature. This property is called specific heat capacity, and water's is among the highest of any common substance.

You need 4,186 joules to raise one kilogram of water by one degree Celsius.

The same energy would raise a kilogram of iron by about 9 degrees Celsius. Water absorbs heat like a sponge and releases it slowly. This is why coastal cities have milder climates — the ocean moderates temperature swings throughout the year.