Spiti experiences a high-altitude cold desert climate (Köppen climate classification: BWk or Dwc depending on specific elevation). Because it lies in the rain shadow of the Greater Himalayas, the region receives negligible rainfall, with most precipitation falling in the form of heavy winter snow.
Winters (November to April) are incredibly harsh and isolating. Temperatures regularly plummet to -30°C (-22°F), freezing the rivers and streams. During this time, the Manali-Kaza road is entirely blocked by snow, and access is only possible via the longer Kinnaur route.
Summers (May to October) are brief but pleasant, with daytime temperatures ranging from 15°C to 25°C (59°F to 77°F), though nights remain chilly. This is the optimal window for agriculture and the primary season for tourism. Natural disasters are typically limited to sudden flash floods from accelerated snowmelt or localized cloudbursts, which can temporarily wash out the fragile mountain roads.
