Gangtok experiences a subtropical highland climate (Köppen climate classification: Cwb). The weather is generally mild year-round, thanks to its high elevation. Summers (April to June) are pleasant, with average temperatures ranging from 15°C to 25°C (59°F to 77°F). Winters (December to February) are cool and crisp, with temperatures usually hovering between 4°C and 14°C (39°F to 57°F). Snowfall in the city proper is rare but does occasionally occur during exceptionally cold winters.
The city is heavily influenced by the Indian monsoon. From June to September, Gangtok receives intense and continuous rainfall, often leading to heavy fog, blocked roads, and landslides. Humidity levels remain high during this period. The best time to visit is during the spring (March to May) and autumn (October to mid-December), when the skies are clear, and the views of the Himalayan peaks are unobstructed.