The Opening Day is Friday , but the first Games are played Wednesday . Soccer is the first sport , with British , American and other teams in attendance . Forecasters say the weather should improve after a rain - soaked summer so far . More than 10,000 athletes from 205 countries are assembling in London for Friday 's Opening Ceremony . Security issues have overshadowed , but authorities say safety will not be affected .
The Opening Day is Friday , but the first Games are played Wednesday . Soccer is the first sport , with British , American and other teams in attendance . Forecasters say the weather should improve after a rain - soaked summer so far . Security issues have overshadowed , but authorities say safety will not be affected .