<p>Road traffic accidents are significantly influenced by meteorological conditions, yet few studies have spatially examined this relationship in data-scarce regions. This study investigates the impact of climatic parameters on road accidents along the Semnan–Shahroud and Mayamey–Jajarm corridors in Semnan Province, Iran. Using Geographic Information System (GIS) tools, eight meteorological variables—including temperature, precipitation, wind speed, snow depth, fog, dust storms, hail, and thunderstorms—were spatially interpolated and overlaid with multi-year accident data (2016–2021). Results indicate that snow depth and wind speed are major contributors to accident risk in mountainous and open plain areas, while fog and precipitation show moderate influence. The study identifies specific high-risk segments and proposes spatially targeted mitigation strategies such as fog detection systems, drainage improvements, and real-time alerts. By integrating climatic and accident data in a spatial framework, this research demonstrates the value of GIS-based analysis for understanding and managing weather-related traffic risks. The findings have practical implications for transportation planning, climate adaptation, and the advancement of spatial information science in road safety management.</p>