贺兰山
Helan County belongs to the mainland climate region. Winters are long and cold, and summers are quite wet. Spring and Fall are relatively short. The average temperature during the summer is , with a record high of . The average temperature in winter is , with a record low of . Daily temperatures are highly variable, changing by an average of 10 degrees Celsius (20 °F) each day. Due to the large variety of topography in the county, regional climates also vary considerably. Notably, winter in the Helan Mountains region can last up to 10 months out of every year.