ORIGINAL ARTICLE Characteristics of Annual and Seasonal Trends of Rainfall and Temperature in Iraq Saleem A. Salman 1 & Shamsuddin Shahid 1 & Tarmizi Ismail 1 & Kamal Ahmed 1 & Eun-Sung Chung 2 & Xiao-Jun Wang 3 Received: 19 March 2018 /Revised: 28 May 2018 /Accepted: 22 June 2018 # Korean Meteorological Society and Springer Nature B.V. 2019 Abstract Changes in the temperature and precipitation have significantly affected water resources and agricultural productions in many countries across the world. The objective of the present study is to analyze the changing patterns of annual and seasonal precipitation and temperature in Iraq for the period 1961–2010. Monthly gridded precipitation and temperature data of Global precipitation climate center (GPCC) and climate research unit (CRU) respectively having a spatial resolution of 0.5° were used in this study to show the spatial pattern in trends. The rate of change in rainfall and temperature was estimated using Sen’ s slope method while the significance of change was confirmed using Mann-Kendal test (MK) and the modified Mann-Kendall test (mMK). The results revealed large differences in the number of grid points showing significant changes in rainfall and temper- ature using MK and mMK methods. The mMK method revealed that the annual rainfall is decreasing at a rate of −1.0 to −5.0 mm/year in the northwest part of Iraq. The seasonal precipitations were found to decrease in spring (−0.4 to −2.56 mm/ year) and winter (−0.4 to −2.0 mm/year), increase in summer (0.06 to 0.21 mm/year) at a few grid points and no change in autumn. On the other hand, a sharp rise in annual average of daily mean (0.42 to 0.64 °C/decade), maximum (0.39 to 0.65 °C/ decade) and minimum (0.36 to 0.69 °C/decade) temperature was observed. Keywords Temperature . Precipitation . Modified Mann-Kendal test . Gridded climate data . Iraq 1 Introduction Trend analysis for climatic variables on different spatial and temporal scales has been a major concern in recent years due to global climate change (Mayowa et al. 2015; Sa’adi et al. 2017b). The global warming is found to affect temperature and rainfall in different parts of the world unevenly. The Arabian Peninsula, largely characterized by an arid climate is supposed to experience faster change in climate due to global warming (UNDP 2013). Even small changes in precip- itation and temperature patterns resulted in heavy floods and long-lasting droughts (Almazroui et al. 2012; Donat et al. 2014 ; Pour et al. 2014 ; Dutta and Chaudhuri 2015 ). Therefore, global warming induced changes in precipitation and temperature pattern can have significant implication in Arabian Peninsula. Responsible editor: Edvin Aldrian * Saleem A. Salman assaleem2@live.utm.my Shamsuddin Shahid sshahid@utm.my Tarmizi Ismail tarmiziismail@utm.my Kamal Ahmed kamal_brc@hotmail.com Eun-Sung Chung eschung@seoultech.ac.kr Xiao-Jun Wang xjwang@nhri.cn 1 Department of Water and Environmental Engineering, School of Civil Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Malaysia 2 Faculty of Civil Engineering, Seoul National University of Science and Technology, 01811 Seoul, Republic of Korea 3 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing, China Asia-Pacific Journal of Atmospheric Sciences https://doi.org/10.1007/s13143-018-0073-4 Online ISSN 1976-7951 Print ISSN 1976-7633 Korean Meteorological Society