Sikkim doesn't have a functional airport. The nearest airport is Bagdogra, situated in Siliguri, West Bengal.
We took an early morning flight from Mumbai to Hyderabad and then another from Hyderabad to Bagdogra. Once we reached Bagdogra, we started our journey towards Sikkim. The daylight in Sikkim is until 5-5.30 PM, so it's best to arrive at Siliguri by noon. Traveling during dark hours is not recommended since the roads are too curvy and dangerous.
The journey from Bagdogra to Gangtok took around 8 hours. Google maps show around 5 hours, but the real-time traffic and road closures due to landslides differ. As we passed through the Siliguri corridor, the road was vivid, beautiful, and full of trees. Once we arrived in Sikkim, we were greeted by the Teesta river, our constant companion as we continued our journey.