Three Decades of Climate Change in Iran: Spatiotemporal Evidence From National-Scale Meteorological Indicators Publisher



Hadei M ; Hopke PK ; Chaparinia F ; Oshidari Y ; Ostadtaghizadeh A ; Hassanvand MS ; Momeniha F ; Aliakbar H ; Naddafi K
Source: Earth Systems and Environment Published:2025

Abstract

Iran is highly vulnerable to climate change due to its dry climate, diverse geography, and ongoing water challenges. This study assessed the climate trends in Iran over the past three decades (1993–2022) by analyzing key meteorological variables. We used daily data measured by the Iranian Meteorological Organization (IRIMO), and used only stations with more than 90% data completeness. Data were examined for significant trends using linear regression and Thiel-Sen slope analyses for 29 provincial capitals and mapped spatially across an expanded network of 69 cities. Results revealed widespread increases in mean temperatures, particularly in central, southern, and western mountainous regions (slopes from 0 to 0.146 °C per year in Isfahan and Zanjan, respectively). All cities in Iran showed an increasing trend in maximum temperature. Minimum temperatures displayed mixed patterns, predominantly increasing in the eastern and northern regions, while decreasing trends emerged in specific areas such as Isfahan. Precipitation exhibited spatially heterogeneous trends, with significant decreases in the southern and central regions and increases in parts of the northeast. Dew point temperatures generally decreased in the central and southern areas, while northern regions saw slight increases. Wind speeds increased significantly in the central, northeastern, and some northern cities, whereas declines were observed predominantly in the southern and western locations. Spatial mapping of decadal averages showed regional variability, highlighting substantial warming and drying trends in several regions. These observed climate changes have important implications for resource management and emphasize the necessity for targeted adaptation strategies to mitigate regional climate risks. © 2025 Elsevier B.V., All rights reserved.