BEIJING -- Environmental officials say their efforts are starting to clear the haze above Beijing, while strong wind and some rain have also raised hopes of blue skies when the Olympic Games start in just more than a week.
The city has put in place a series of drastic pollution controls since July 20 that included pulling half the city's 3.3 million vehicles off the roads, halting most construction and closing some factories in the capital and surrounding provinces.
But Beijing has been dogged in the last week by a persistent haze that cloaked the city, threatening assurances by Chinese authorities that skies will be clear when the games start Aug. 8.
Tuesday's relatively clearer skies highlighted how much weather conditions play a part in the overall equation for curbing pollution. Winds and rain were a "major factor" in causing pollutants to dissipate, said spokeswoman Zhai Xiaohui with the Beijing Municipal Environmental Protection Bureau.
The government has worked on cloud seeding to control rain, but has acknowledged the wind remains an unpredictable factor.
A top environmental official said Tuesday that the air in July had greatly improved when compared to the same month last year.
"After the adoption of these measures, we have seen visible improvements," Du Shaozhong, deputy director of Beijing's Environmental Protection Bureau, told a news conference.
There have been 25 days of clean air in July, two more than the same period last year, he said. Du did not say what constituted clean air, but said since July 1, major pollutants have been reduced by 15 to 20 percent.
Tian Jun, 26, who works in sales at a downtown hotel, said Beijing's air had improved overall in the last three to five years. The Olympics have helped because they enabled the government to move industries outside of the city and plant more trees, as well as limit the number of cars, he said.
"The government has done a good job," Tian said, standing outside a cafe with his friends. "It should continue after the Olympics."
But Frederick Szeto, a consultant from Hong Kong who has been in Beijing for nearly two months, said he doubted the restrictions could have already made such a difference.
"If this could last until fall, then that would be good," he said. "I think it's because it's rained, not because of the air quality."
The city's chronic air pollution has been a source of concern for Olympic organizers. The games will bring 10,500 athletes and hundreds of thousands of spectators to Beijing.
Highlighting Beijing's fears that air quality won't improve in time, Du said a contingency plan has been devised and could be implemented as part of last-minute emergency measures if needed.
The official China Daily newspaper said Monday that Beijing could pull even more cars from the roads and shut down additional factories as part of last-ditch efforts.
The air pollution index for particulate matter, a major pollutant, dropped to 90 on Tuesday from 96 on Monday, after reaching 118 on Saturday, a level classified as unhealthy for sensitive groups.
An API below 50 is considered good air quality and between 51 to 100 is moderate, according to the Web site of the city's Environmental Protection Bureau. But critics say even moderate levels are still above the World Health Organization's guidelines for healthy air.
Associated Press reporter Chi-Chi Zhang contributed to this story.