This is the CMB and it has a nearly uniform temperature across the entire sky: a very cold -270.45 deg Celsius.

BBC: Pictures of the early Universe

Another anomaly of these results is that temperature fluctuations are not uniform across the sky map.

CNN: Better 'baby picture' of universe emerges

But it requires a huge amount of energy to change the temperature quickly, and the temperature isn't always precisely uniform across all the samples in the instrument.

FORBES: Technology

It still bathes the Earth in a near-uniform glow at microwave frequencies, and has a temperature profile that is just 2.7 degrees above absolute zero.

BBC: Planck satellite: Maps detail Universe's ancient light