Climate change-induced variabilities and most recent normal in climate extremes using ERA5-Land reanalysis data in Syria from 1950 to 2024

Syria is highly vulnerable to climate change; however, long-term assessments of climate extremes remain limited due to the scarcity and incompleteness of meteorological observations. This study addresses this gap by analyzing temperature- and precipitation-related extremes from 1950 to 2024 using the high-resolution ERA5-Land (~ 9 km) reanalysis dataset. Using 15 ETCCDI-recommended indices, changes in cold/warm temperature extremes, as well as in heavy rainfall and dry spells, across Syria’s main climate zones are quantified. Trend analysis was performed using Sen’s slope to estimate trend magnitude and the Mann–Kendall test to assess statistical significance (p ≤ 0.05 and 0.05 < p ≤ 0.10). Results reveal widespread warming, with consistent decreases in cold extremes (e.g., FD) and increases in warm extremes (e.g., TN90p) across most regions, indicating a robust intensification of heat-related extremes. Precipitation extremes exhibit strong spatial heterogeneity: Syria shows shorter dry spells (Consecutive Dry Days decrease) and shifts in the occurrence/intensity of heavy precipitation (e.g., Rx1day), whereas coastal and mountainous regions show changes in wet-spell structure and seasonal precipitation behavior. These findings underscore the growing climate risks to agriculture and water resources, including heightened exposure to heat stress, drought, and localized flooding. This study provides a comprehensive long-term baseline for climate extremes in Syria using ERA5-Land and supports climate adaptation planning in data-scarce regions.