We have all been taught that water freezes at 32 degrees Fahrenheit, 0 degrees Celsius, 273.15 Kelvin. That's not always the case, though. Scientists have found liquid water as cold as -40 degrees F in clouds and even cooled water down to -42 degrees F in the lab.
Mercury is the only metal that is in liqid form at room temperature. Caesium, Gallim and Rubidium are also metals that are in liquid form but at slightly high temperature than the room temperature.