On the long-awaited day that these Olympics officially opened, the sky was smoggy and the local air quality rating was 94, well above the limits in the United States. Still, anything below a 101 qualifies as a “Blue Sky Day” here, according to the standards set to monitor air quality for the Olympics.

Local environmental officials said at a hastily organized news conference that they were happy with the air quality here, after so much effort to clear the air for these Games.

“We have gone through a very extraordinary process to improve its air quality and we have achieved outstanding results,” said Du Shaozhong, deputy director and spokesman of the Beijing municipal environmental bureau.

Du said Beijing had met the World Health Organization’s international standards of air quality, which was what the Beijing Olympics organizers had promised the International Olympic Committee in 2001, when the city was awarded the Games. Later, Du said that the city had met the standards set in 1999, not more updated standards that include measures of tiny dust particles that cause most of the pollution here.