This document has been produced as a supplement to “Guidelines on Biometeorology and Air Quality Forecasts” WMO/TD No. 1184. It addresses the specific aspects of human biometeorology related to human disease, which was not included in that publication. It should be consulted in conjunction with WMO/TD No. 1184. The guidelines are intended to provide useful advice to National Meteorological and Hydrological Services (NMHSs) on methods of incorporating air quality forecasts and biometeorological information into the suite of products and services offered to the public. The Public Weather Services (PWS) Expert Team on Product Development and Service Assessment developed the original guidelines at the request of the Commission on Basic Systems (CBS). This supplement was developed by the Public Weather Services (PWS) Expert Team on Services and Products Improvement. It is acknowledged that several NMHSs already provide this type of information while others are on the verge of developing an air quality programme. However, all NMHSs should find this document useful, especially those in developing countries that are seeking to develop or improve their national public weather services delivery while, at the same time, attempting to come to terms with some aspects of the widening array of environmental issues.