This apparent correlation depends on adjustments to the data, however, and it does not hold up (PDF) when more recent cloud measurements from 1996 onwards are included. (newscientist.com)
When the correct adjustments to the data were applied the data matched much more closely the trends expected by climate models. (skepticalscience.com)
The surface record does not have a history of making major adjustments to the data like the atmosphere data do. (skepticalscience.com)