The highest recorded API readings 212 Central, yesterday 192 Central, May 29, 2011 186 Causeway Bay, February 5, 2011 184 Causeway Bay, February 2, 2011 183 Mong Kok, April 22, 2012 182 Mong Kok, November 3, 2003 179 Causeway Bay, January 15, 2011 178 Central, May 28, 2011 Source: Environmental Protection Department