Hanoi’s winter is not cold by northern-European standards, but it is cold in a way that surprises visitors: 12–17°C, humid, with weeks of drizzle and roads that never fully dry. The rental-side winter picture is in renting-motorbike-hanoi-winter; this is the riding-craft version.
Cold hands brake badly
Wind chill at 40 km/h in damp 13°C air makes hands numb within half an hour, and numb hands squeeze brakes late. Waterproof gloves solve both problems at once. A windproof layer under a normal jacket does more than a thick one over it. Cold tyres also grip less until they warm — take the first kilometres gently.
The endless damp
Winter drizzle leaves a film of water and road grime everywhere: braking distances are permanently longer, painted lines stay slippery, and the drizzle gives up just often enough to fool you. Treat every surface as wet even when it looks dry. The wet-riding techniques in riding-motorbike-heavy-rain-vietnam apply at half intensity all winter.
Low light, low visibility
Winter Hanoi is grey, and the damp air plus early darkness shrink visibility for everyone. Lights on all day — the law requires working lights after dark, per motorbike-night-lights-vietnam — and assume the grey mass around you hides unlit bikes. Drizzle thickening into fog has its own article: fog-and-low-visibility-riding-motorbike-vietnam.
Bike care
Winter damp is hard on chains and exposed metal — chain-maintenance-motorbike-vietnam covers the routine that keeps a winter bike quiet. Keep your helmet somewhere dry; a damp liner never fully dries until March.
The one-line version
Waterproof gloves, a windproof layer, lights on, brakes covered — Hanoi winter is a drizzle marathon, not a cold snap, so ride like the roads are permanently half-wet, because they are.