Beijing saw 27 "blue sky days" in May, the most in 10 years, according to a report released by Beijing Municipal Environmental Protection Bureau on Tuesday.

According to the bureau's statistics, the overall air quality of Beijing in May was better than last year, with six more days of blue skies than were recorded in May 2010.

However, there were also several days with poor air quality as the result of warm fronts coming in after a cold spell that occurred during the first part of the month, according to the bureau's report.

May 1 saw the lowest air quality for the month, with dust being blown in from neighboring regions, the report said.

As of Tuesday, Beijing has enjoyed 118 days of "good" air quality in 2011, four more than were recorded during the same period last year, according to the report.

A "blue sky days" target has been set to encourage the city to improve its environment. Authorities are aiming for 274 "blue sky days" this year, according to the report.