What to pack for San Francisco in January

Lows around 46°F. Goes under the shell when the wind picks up.

Wear one, dry one. Cotton stays wet all week here.

The layer you'll wear more than any other.

Wind at 22 km/h and lows of 46°F make an uninsulated head lose heat fast.

Water reflects light even on overcast days, and 9.8 hours of daylight means glare all afternoon.

Mosquitoes breed in the bay marshes nearby and don't vanish until hard frost hits.

Check ankles and, if there's a dog, paws and ears every night.

Wet streets and 9.8 hours of walking each day raise the odds of minor injuries.

Nine hours of daylight means your phone camera gets heavy use and drains fast.

Dark by 6:15pm. Every campsite chore after that is a two-hands job.

Eleven rain days soak through day packs, so a larger bag with a rain cover keeps gear dry.

Fits the overhead on every airline that matters. Skip the checked-bag line entirely.

For the passport, the chargers, and the one dry pair of socks.

Coastal wind and 46°F lows chill the neck and face before the rest of you feels it.

Treat the clothes once and it lasts weeks.

Tap water is safe here, so a bottle cuts down plastic waste over a month.

One brick charges the laptop, phone, and camera.

Urban crowds and short daylight hours make it easy to misplace a bag.

Rain on 11 days means damp clothes pile up fast without a system.

Humidity at 82% makes clothes smell sour if you wait more than two days.

Lows around 46°F. One blanket that packs small covers the car, the campsite and the beach at sunset.

Layers work better than one thick coat when the day swings from 46°F to 57°F.

High humidity at 82% and salt air make skin prone to infection from small cuts.

Insect bites itch worse in cold, damp air and scratching breaks the skin open.

A power bank needs its own cable, separate from the one you use daily.

Domestic travel through a major airport requires a lock that airport staff can open.

Guesthouses have one bathroom and limited counter space for morning routines.