Semnan is capital of Semnan Province. Semnan is located in the central northern portion of Iran. The city serves as the cultural and political capital of the Semnan Province. The city of Semnan is situated just south of the foothills of the Alborz Mountains, bordering the Kavir Desert to the south of the city. The city of Semnan enjoys the traditional four seasons of spring, summer, winter, and autumn each year. The rain season starts in December and lasts all the way into May, however, precipitation throughout the winter months generally falls in the form of light snow, and the rest of the precipitation throughout the rain season is generally very light to moderate.

During some winters, moisture-abundant blizzards make their way down from the Alborz mountains from the north of the city and dump several centimeters of snow in a single twenty-four hour period. These blizzards force the closure of the airport, schools, small streets, and alleyways. Spring is characterized by mild to warm day temperatures and cold to cool nights along with a reduction in precipitation as the season transitions into Summer. Summer is often characterized by hot daily temperatures and warm nights. Summer months remain dry with trace amounts of rainfall. Autumn is also a transitional season in which the daily temperatures range from hot to cool along with cool nights.