Abstract: The characteristics of spatial-temporal variations of hazes in Shandong Province were analyzed by using the surface observation data from 1961 to 2005 and employing the EOF method as well as other statistical methods. The results indicate that the average annual haze days was higher in the middle and south of Shandong Province and lower in the north of Shandong Province and most of the Shandong Peninsula. Hazes mainly occurred in autumn and winter. Hazes showed a generally rising trend over the past 45 years, but a slightly falling trend after 2000. The inter-annual variation of hazes was obvious. When a haze occurred, the visibility mostly ranged from 5 to 10 km, and the relative humidity ranged from 70% to 90%. The day number of hazes was proportional to temperature, but inversely proportional to wind speed.

Key words: haze, EOF analysis, spatial-temporal variation, Shandong Province