Monsoon or dry season in North East India

Rainfall varies enormously across the region. Sohra, on the southern edge of the Khasi Hills, averages about 11,000 mm a year, and in June and July each month brings around 2,600 mm, more than Guwahati receives in a whole year. Guwahati, in the Brahmaputra valley, gets about 1,700 mm a year. Tawang, behind the main Himalayan ranges, is wetter than you might expect in summer but dry and very cold in winter.

The table shows approximate monthly rainfall at four places, based on long-term averages. Use it as a guide to how wet each place is, not as a forecast.

These are the region's most dependable months. Rain is almost absent, skies are clear and mountain views are at their best, especially in October and November after the monsoon has washed the air. Kaziranga is fully open by November, and burnt grassland from December improves wildlife viewing. In Meghalaya the steps to Nongriat are dry, the Umngot at Dawki runs glass-clear, and walking days are comfortable at 15 to 20 °C.

There are trade-offs. Nights are cold in the hills: around 5 °C in Shillong and Kohima, and well below freezing in Tawang and Lachung, where snow can close roads for a day or two. Meghalaya's waterfalls are much thinner by January, and some, like the Seven Sisters, may dry to a trickle. Demand is high, especially in December for the Hornbill Festival and at Christmas, so book the best rooms early.

October and March to May are often overlooked and can be excellent. October brings the clearest air of the year in Sikkim and Arunachal, full waterfalls in Meghalaya and the reopening of Kaziranga, though some ranges may still be closed early in the month and Durga Puja fills Guwahati and Shillong with crowds.

March and April are spring. Sikkim's rhododendrons flower, tea plucking begins in Assam, and festivals such as Bihu and Shad Suk Mynsiem fill the calendar. Pre-monsoon thunderstorms arrive in the afternoons, rainfall climbs steeply in Meghalaya from April, and humidity rises in the plains. May is the month to go high: Tawang, Dirang and Yumthang are mild and green, while Kaziranga usually closes and Sohra's rain builds towards the monsoon.

The monsoon transforms the region. Hills turn a deep green, waterfalls appear on every cliff in Meghalaya, and cloud flows through the gorges. For a small number of travellers, this is the reason to come, and a short stay in Shillong or Sohra to watch the rain from a good room can be memorable.

For most journeys, though, the monsoon brings real problems:

• Kaziranga, Manas, Nameri and Pobitora close from about May or June to October.
• Landslides affect NH-6 to Shillong, NH-13 to Tawang and NH-10 into Sikkim, sometimes for days.
• North Sikkim is often closed after landslides, and has been badly affected since the 2023 Teesta flood.
• Ferries to Majuli can be suspended when the Brahmaputra rises.
• Trails such as Nongriat become slippery, and some close.
• Fog hides views, and humidity in the plains is high.

If your heart is set on one region, choose your months accordingly. For Kaziranga and the Assam plains, come between mid-November and April. For Meghalaya, October to March gives the best balance of dry paths and flowing water, with November and December the sweet spot. For Tawang and western Arunachal, March to May and October to November are best. For Sikkim, October to December gives clear Kanchenjunga views, and April to May brings rhododendrons. For Nagaland, the Hornbill Festival fixes December.

Combining regions narrows the window. A journey across Meghalaya and Kaziranga works from November to March. Adding Tawang favours November, March and April. Sikkim and Meghalaya together suit October, November and March.

Festivals can tip the balance. The Ziro Festival of Music in late September rewards travellers willing to accept some rain. Majuli Raas falls around the November full moon, Hornbill fixes the first ten days of December, Losar in Tawang comes in February or early March, and Rongali Bihu and Shad Suk Mynsiem bring April to life in Assam and Shillong. Ambubachi Mela at Kamakhya, in late June, is the one major event of the monsoon, and it is intense, crowded and wet. If a festival matters to you, start with its dates and build the rest of the journey around them, accepting the weather that comes with that month.

For November to February, pack for two climates. In the Assam plains, days are mild and dry, so light layers, a sun hat and a warm jacket for open jeeps at dawn are enough. In the hills, add a proper warm layer for evenings in Shillong and Kohima, and thermals, gloves, a down jacket and a warm hat for Tawang, Lachung or Pelling at sunrise.

For March to May and October, pack light clothes for warm afternoons, a rain jacket for pre-monsoon storms or late showers, and a fleece for the hills. Walking shoes with good grip matter year-round in Meghalaya, where paths are often damp. In the monsoon, add a sturdy umbrella, quick-drying clothes, waterproof shoes and dry bags for phones and cameras.

Whatever the season, bring insect repellent for dusk in the plains and tea gardens, sunscreen for high altitude, and a refillable water bottle, which is required in parts of Sikkim where plastic bottles are restricted.

If you have a choice, travel in November. Rain is nearly absent, the air is clear after the monsoon, Kaziranga's main ranges are open, the Umngot is clear, the Majuli Raas festival takes place, and the mountains of Sikkim and Arunachal are sharp against blue skies. Book the best rooms by June.

Whatever the month, build in flexibility. A spare day on a mountain journey, refundable bookings in the monsoon and a willingness to swap one valley for another will protect your trip from the region's weather, which no forecast fully predicts. Check current status before you travel.