What clothes should i wear in 1st july - 7th july 2011 in Beijing?

It is the hottest month in Beijing in July. The hot weather calls for cool clothes as the temperature in July ranges between 22 C and 31 C . Short and heavy rainstorms frequently happen without warning in the afternoon of sunny days. Sometimes even weather forecasters can predict a shower only one or two hours ahead. Remember to pack a raincoat or umbrella, and you should prepare for traffic jam caused by heavy rain.