January is the middle of winter and the coldest month in Nepal. Most people do not go trekking in Nepal for several reasons such as fearing the extreme cold, heavy snowfall, which raises concerns about safety. Little do they know that January is one of the best months to go trekking not only in Nepal's lower altitude trek such as the Ghorepani route, Mardi Himal, Everest Panorama but also some of the well-trodden paths such as Gokyo Lakes and Everest Base Camp or Everest Base Camp or Annapurna circuit with Tilicho lake.
The last decade has seen a decrease in snowfall in January. There is precipitation for a few days every month where it rains in the lower elevations while it snows in, the higher mountains.
It is good to dress up in layers, which you can ‘peel' one at a time when you start to warm/heat up as you begin trekking.
A friend and I personally did a winter trek of Annapurna Circuit with Tilicho Lake this January with relative ease. These days most lodges have Internet connections with WIFI facilities; it is easy to check the weather forecast in advance. The online weather apps claimed temperatures to be -18 in places like Manang 3500 meters or even -24 on the Thorong La pass at 5416 meters. We were warm with our sleeping bags and an extra blanket. We were comfortable walking during the day and even perspired on uphill climbs. It is always better to be over prepared rather than under prepared.
What to expect while trekking in January?
You can expect the temperatures to be colder and this ensures the clouds stay low, which makes the view of the mountains visible for most of the day if not all day for several days.
The trekking trails and the lodges will be less crowded which makes it pleasant. There will be no queue for hot showers; your meals will be served faster. You might even have the lodge to yourself.
Try to have additional days if you intend to do high altitude treks, the weather in the mountains can change with little warning. Sometimes snowfall can cut off high passes for a few days.
Beware of icy conditions on the trail when trekking in winter. Be extra careful when you pass villages in the higher altitude above 2500 meters, the villagers leave the communal taps running to prevent it from freezing and pipes breaking, and this can make the area near the faucet very icy and sleek.
Will the lodges and restaurants on the trekking trails be open?
Most lodges and restaurants in the lower elevations will remain open. In the higher altitude villages, some hostels are closed as the owners go to warmer places like Kathmandu, Pokhara or Chitwan. Some of the lodges are left to the employees to run it during the winter off-season. You don't have to worry; there will be some lodges that are open in the higher villages; otherwise, the person running the hostel if the lodges on your way are all closed will inform you.
What equipment to bring for Nepal trekking in January?
You are advised to dress up in layers during winter trekking in Nepal. It can be sunny during the daytime making it easier to take coats off as you begin to warm up. Good trekking boots are advised in preparation for possible snow and ice along with thick socks. Thermal underwear, in fact, Merino wool products are a good investment if you are planning to hike in the high altitude areas. They are supposed to stay odorless for up to two weeks; these will help if you feel the cold and can't take showers for extended periods. Good windproof jacket along with a thick winter trekking jacket or down jacket will be helpful. Bring a suitable sleeping bag, if you feel cold, blankets are more readily available than during the peak season for additional warmth – do be warned, and some quilts can be smelly.
You are expected to eat at the lodge you plan to spend the night. They have a higher charge if you eat outside as their profit comes from your meals rather than from the room charge.
Do I still need Trekking permits?
Yes, you will need trekking permits throughout the year. It is available in Kathmandu and Pokhara. You are also advised to have proper travel insurance that covers helicopter evacuation in case of illness, accident, natural calamity or political uprising.
Update: January 2019: It snowed in the areas of Eastern Himalayas on the 1st and on the 3rd of January. January 2019 experienced a good amount of rainfall and snowfall like it use to two decades or more ago.