Olympic cyclists face better conditions than on the weekend for Wednesday's road race but the dressage riders will be sweating in their uniforms in Hong Kong, the dpa reported.
Temperatures in hazy Beijing and at the time trial course outside the capital near the Great Wall will reach 30 degrees celsius, but the humidity is not to be oppressive at 60 per cent.
The men's road race on Saturday was held in hot and humid conditions, the women's race the next day in driving rain.
A few drops of rain could fall on Wednesday which would mainly affect the tennis competition.
The start of Olympic dressage in Hong Kong will take place under sunny skies on a hot day with temperatures to soar well over 30 degrees. Sailors in Qingdao will compete in a light breeze.