What is the coldest it has got ever?

Answer 1

Outside a laboratory where temperature can be controlled, the coldest temperature ever recorded on earth was recorded at the Soviet Vostok Research Station in Antarctica on July 21, 1983. It was recorded as −89.2 °C (−128.6 °F; 184.0 K).

2nd Answer:

True, and that is the answer you were probably looking for, but when the world was young, billions of years ago, the oceans formed. The atmosphere back then took up millions of pounds of water vapor from the oceans. Due to other concerns, the young Earth was then subjected to an estimated 100,000 years of nearly continuous snowfall, turning the Earth into a big iceball of ice maybe 1/4 mile thick.

Most likely, it was far colder back then, but there was no one to take the temperature. Also, there were no thermometers.