روند ميانگين سالانه پوشش ابري آسمان و كاهش ميانگين الانه دماي حداكثر در تعدادي از ايستگاههاي كشور

The meteorological and climatological investigators not only analyze changes in the air temperature over a period of time, also interested in other climatological parameters such as cloudiness, which plays an important role in the air temperature flactuations. The statistcal analyses derived from climate changes in Iran from 1951 to 1997 show that the mean annual maximum air temperature in several meteoroloical stations, especially the coastal stations, tends to decrease. Similar trend in decrease in mean annual maximum air temperature has been reported in several other countries including China, that is due to Cloudiness and an increase in precipitation/ rain. This paper will examine the role of cloud cover annual averages on mean annual maximum air temperature changes in several meteorological stations in Iran. The results show that there is a negative trend of mean annual maximum air temperature with positive trend of cloud cover annual averages in costal stations include Abadan and Bandar Anzali, but in Isfahan station, mean annual maximum air temperature tends to decrease with similar trend in decrease in cloud cover annual averages.