As Anthony Watts explains here:
January was cold. Very cold. probably becuase of a combination of factors, but especially: La Nina, shift to cool PDO (Prediction! warm summers in Alaska are over for then next 30-50 years! US will warm less than expected (although AMO is still positive, so it will stay warm)! ) and yes, all this coincides with a Solar Minimum. All we need is a well timed Volcano in the next few months, me thinks, to see 2008 be a very cold year indeed! (Note, I haven’t checked yet, but the story may or may not be different from UAH). Maybe a couple of Pinatobas or a Krakatoa and we’d totally offset AGW for a while! More seriously, this just demonstrates again the importance of these factors for temperature variations.