China has never been known as a country with the cleanest air. Their smog reportedly kills 4,000 people every day.

But that all changed for a bit in Beijing on August 20, when 5 million cars were forced to drive on alternating days and restrictions were implemented on factories in order to decrease pollutants in the city. These restrictions happened for the next two weeks until September 3, which is the annual China’s Victory Day parade marking the 70th anniversary of Japan’s defeat in World War II.

Here were the results of the ban:

For the first time in what seemed like forever, there were blue skies, and buildings became clearly visible from the lack of the usual smog. The blue skies were nicknamed “parade blue” by netizens.

During the ban, 40,000 construction sites were also shut down.

Air quality improved drastically. On the day of the parade, the city’s air quality index sunk to 17 out of 500, signifying healthy air.

Beijing’s average levels of PM (particulate matter) also dropped by 73.2% compared to last year, according to Zhang Dawei, head of the Beijing Municipal Environmental Monitoring Center.

Zhang Wei added: “It was as good as the annual index in some metropolises in developed countries, such as Paris, London, Moscow and Singapore.

Unfortunately, when the bans were lifted a day after the parade, the air quality index rose to 160 out of 500, a level at which “everyone may begin to experience some adverse health effects,” according to the U.S. Environmental Protection Agency. Suddenly, as fast as they appeared, the blue skies were gone and covered by the familiar, thick smog.

But, there may be light at the end of the tunnel. In July, China announced plans to spend 1.7 million yuan ($230 billion) on air pollution controls over the next five years.