The stretch of the Sultan’s Trail between Belgrade and Sofia mixes open lowlands and river plains with rising foothills and villages, bringing shifting weather and changing underfoot conditions. April, May, and September often bring milder temperatures, longer daylight, and steadier day‑to‑day progress. Summer can be hot with fast storms on exposed sections, while late autumn through winter turns colder, wetter, and more changeable, with shorter days, occasional freezing rain or snow, and sporadically limited rural services.