Brahmaputra Valley · Eastern Himalaya & Brahmaputra Belt
Terrain and eco-zones
Humid subtropical, with 1,800 to over 3,000 mm of rain a year. The pre-monsoon Bordoisila storms arrive in April, and the monsoon from June to September regularly floods large parts of the valley — a destructive cycle that is also what renews the soil. Winter is mild, foggy and dry.
Landforms
Brahmaputra valley — around 80 km wide, 700 km longBarak valley in the southKarbi Anglong plateau and the Dima Hasao hillsMajuli — the largest river island in the world, and shrinking to erosionChar lands — impermanent sandbar islands, inhabited and re-formed every year
Rivers and waters
Brahmaputra (Luit) — braided, and among the widest rivers anywhereBarakSubansiri, Manas, Dhansiri, Kopili, Jia BharaliDeepor Beel — a Ramsar wetland on Guwahati's edgeSon Beel — one of the largest wetlands in the northeast
Through the year
| Season | Months | Typical | What it is like |
|---|---|---|---|
| Spring (Bohag) | March–April | 18–30 °C | Bordoisila thunderstorms, and Rongali Bihu in mid-April. Everything is green and unsettled. |
| Monsoon | June–September | 25–33 °C | Heavy, sustained rain and flooding. Kaziranga and Manas close for the season, roughly May to October. |
| Autumn | October–November | 20–30 °C | Clear, dry, sharp light. Kati Bihu, Raas at Majuli, and the parks reopening. |
| Winter | December–February | 8–25 °C | Cool, foggy mornings; the best wildlife viewing and the best tea-estate weather. Magh Bihu in mid-January. |
Best time to visitNovember to April. Kaziranga and Manas are open roughly November to April; Majuli's Raas festival is in November; Rongali Bihu is mid-April, and is the single best week to see the state as itself.
The climate, landforms, rivers and seasons of Brahmaputra Valley, and the best time of year to visit. (4)