Rockets are being fired high into the sky - just as they were during the 2008 Beijing Olympics - to seed chemicals in the atmosphere that form rain clouds. It takes about five to 10 minutes after the rocket launches for water crystals to form into large enough clouds to start the "artificial rain". So far the efforts are working well.
Temperatures in Nanjing have hit 40 degrees Celsius and have already left at least five members of Hong Kong's team struggling with heatstroke. Forecasts suggest the hot weather will continue throughout the Games.
Ronnie Wong Man-chiu, the team's Chef de Mission, said he is not too worried about the hot weather, despite the need to create artificial rain. "It's the same problem for all the teams," he said. "So we all have to adapt to it. Hong Kong is a place that's used to high temperatures, so our athletes should be fine with the conditions."
Last Thursday, Hong Kong's handball squad were present to receive the official welcome at the Athletes' Village, on behalf of all of the city's 102 athletes competing in Nanjing. The boys' football team also arrived early, but the majority of Hong Kong's athletes, plus more than 50 officials and coaches, were still travelling.
Tse Ka-wing, 14, a Form Two student at Confucian Ho Kwok Pui Chun College, who is a goalkeeper in the boys' football team, said: "It's great to be here. The multisport Games are a wonderful experience. I hope that being part of the team will help in future when I'm trying to apply to go to university."
Wong said he hopes the whole Hong Kong team will "learn and grow" from their experiences during these Games, which - for some competitors - are a warm-up to next summer's Youth Olympic Games, also to be held in Nanjing.
"For our athletes, friendship should always be the main goal," Wong said. "They should certainly make the most of this experience.
"Results, too, are important. I think we certainly have a good chance to win medals in a number of events, especially swimming, fencing and rugby sevens."
Hong Kong's swimming team won 14 of the total of 18 medals that the city claimed at the first Games held in Singapore, in 2009.
Wong, who is also honorary secretary of the Hong Kong Amateur Swimming Association, expects improved performances from all the nations' competitors. "Some countries may not have sent their top swimmers last time, so this time we'll be under greater pressure if better competitors come," he said.
"However, I have great confidence in our swimmers doing well here; we are one of the leading swimming teams in Asia."