Abstract: On the basis of quality control of hourly temperature datasets from 67 Automatic Weather Stations (AWSs) in the last four years (2007-2010), the characteristics of diurnal temperature variations over urban and rural areas in Beijing are analyzed. The statistical distributions of the time of maximum high temperature and minimum low temperature in the daily cycle, which are the two most important characteristic values describing the diurnal variation, are analyzed. The difference in diurnal temperature variation between urban and rural areas in Beijing and its seasonal change are investigated using the results. Further, the characteristic diurnal variations in the temperature change in different units of time is studied, as well as their statistically determined emergence times. The different influences in urban and rural areas are also discussed. The results revealed the following. The maximum high temperature generally appears earlier in rural areas than in urban areas, but the minimum low temperature occurs later in rural areas than in urban areas. Compared with that in rural area, the characteristics of diurnal temperature variation are more concentrated for the AWSs in urban areas. The emergence times of the maximum high temperature and minimum low temperature also exhibit greater agreement for AWSs in urban areas. The characteristic diurnal variations change obviously with the season. For the maximum high temperature, the emergence time is centralized in autumn and winter but dispersive in spring and summer. The trend is the opposite for the minimum low temperature, which is centralized in spring and summer but dispersive in autumn and winter. The positive and negative temperature changes are asymmetrical on a daily cycle. The temperature shows a sharp rise but a slow decrease during a day. Urban areas typically have a smaller temperature range than rural areas in spring and autumn but not in summer and winter. Analyses of the temperature change rate in different time intervals showed that the sharpest change takes place in three hours. The statistical pattern of the time at which the maximum positive temperature change appears is different from that for the negative change. The time at which the maximum positive (negative) temperature appears is the most concentrated in winter (autumn) but the most dispersive in summer (spring). The differences between urban and rural areas in the characteristic diurnal variations in the maximum high and minimum low temperatures and the characteristics of temperature change are caused mainly by the larger thermal capacity of urban areas. Investigation of the characteristics of diurnal temperature characteristic and its differences in different seasons and different regions is important for better understanding of regional climate and the influence of urbanization. It can also provide climate background for refined weather forecasting.