Effects of Climate Change on Warming and Rainfall Patterns; Iran Case Study

The analysis investigates lasting climate trends underlying the importance of territorial coincidence of trend changes among temperature fluctuations, (minimum, average, and maximum) and precipitation observed in the past four decades at eight major meteorological stations in Iran. Applying the Mann–Kendall trend test indicated a steady increase in annual temperatures, while a general decline in annual precipitation in all territories of Iran. These dual trends vary across the study stations, strongly affected by altitude, latitude, and regional climate zones. In this case, high-altitude northern stations reached the highest rising trends in maximum temperature, as well as significant decrease in precipitation was observed. In contrast, lowland southern stations showed a weaker warming trend and also observed smaller changes in their precipitation. Only two stations, Tehran and Mashhad, with the highest urban density, showed sharper nighttime warming trend through an increase in minimum temperatures, which could highlight the role of local dynamics influenced by urbanization growth. Overall, the combined results of temperature and precipitation trends highlight that the mountainous regions located in the higher latitudes tend to be riskier concerning the increase in daily maximum temperature and decrease in precipitation amount. In general, these local differences in changes in temperature and precipitation are influenced by two main factors: altitude and latitude, which therefore emphasizes the need for climate adaptation strategies tailored to the geography and topography in each diverse ecosystem.