Participants are requested to predict concentration levels of several pollutants, include PM2.5, over the coming 48 hours for two cities: Beijing, China, and London, UK. On each day throughout the competition, air quality data and meteorological data for both cities will be provided on the hourly basis. For example, on May 14, the participants will be able to access historical data up to May 14 (including), and will have to predict the pollution level for May 15 and 16. Over a period of 24 hours (by 23:59 UTC), each team will be allowed to make no more than 3 submissions to predict 48 hours of air quality results, starting from 0:00 UTC of the next day. You can more details on the submission API and the submission file format on the 'data' page or in this tutorial.