Organisers have long claimed the weather won't spoil London's party, but the guests of honour evidently don't agree.
China's superstar 110m hurdler Liu Xiang has abandoned his training camp due to the cold, says Chinese media.
Xiang has disappeared to Dusseldorf in Germany, just a few days after arriving at St Mary's University College, Twickenham, where members of the South African, Japanese and Irish teams are also preparing.
"Due to low temperatures, many Chinese athletes and other teams have chosen to look for other bases. Liu is not the only one," his coach Sun Haiping said.