Beijing residents have been breathing some of the cleanest air in a decade as they begin to reap the benefits of China's anti-smog push.

Of the seven lowest monthly pollution readings in the capital city since 2008, five have been recorded since the beginning of last summer, according to data gathered by the U.S. Embassy in Beijing. That's when Chinese officials ramped up enforcement of policies restricting coal burning in Beijing and surrounding areas. July pollution levels averaged 44 micrograms of airborne particles per cubic meter — the seventh lowest since recordings began in 2008.

The improved air quality underscores how rapidly China is attacking the smog problem that in 2013 created Beijing's "airpocalypse," when the tiny particles peaked at 35 times the World Health Organization's recommended limit. Since President Xi Jinping made fighting air pollution one of the country's main priorities, millions of northern businesses and families were forced to switch from coal to cleaner-burning natural gas for industrial power and home heating.