Short answer
December to February is cold, with possible frost on the high plateau. The Loop gets very busy around the Tet holiday.
When it happens
Winter in Ha Giang runs from December through February. The most significant event during this period is the Lunar New Year (Tet), which usually falls in late January or February. The exact dates of Tet shift each year based on the lunar calendar.
What to expect
The high plateau gets very cold. In December and January, you may even encounter frost at higher altitudes. Make sure to pack plenty of warm layers, as many guesthouses do not have central heating.
During the Tet holiday itself, the Loop becomes very busy with domestic travelers. At the same time, many local shops, restaurants, and mechanics may close for the holiday.
Practical & safety notes
Riding in the cold requires good preparation. Wind chill on the mountain passes will make it feel much colder than the forecast suggests. Wear windproof and insulated clothing. Because of the holiday crowds around Tet, you should book your accommodation well in advance.
Note
Tet follows the lunar calendar — check the exact dates for your year. Frost on the plateau: see Meo Vac has frost (SGGP).
Frequently asked questions
How cold does it get in winter?
It can be very cold, and frost is possible on the high plateau in December and January.
Can I travel during Tet?
Yes, but expect it to be very busy and for many local shops or services to be closed.