Changes and trends in maximum, minimum and mean temperature series in Iran

The variations of Iran temperature is studied during 1961–2010. Mann–Kendall tests show a general dominating positive temperature trend over most parts of Iran with the rate of change varying from 0.09 to 0.38 °C decade −1 . Also, the minimum temperature increase (0.34 °C decade −1 ) is greater than maximum temperature (0.15 °C decade −1 ). A more definite trend of warming occurs in summer and spring than winter and autumn. Moreover, the results show that the warm climate regions in Iran are warming at a higher rate than cold climate regions. Pettitt's test also suggesting the abrupt upward change in mean annual temperature, occurs in the late 1990s.