Honestly, if you're planning to be out and about in the city, tomorrow is looking pretty decent for January. We often expect the worst this time of year—sideways rain, bone-chilling fog, the works. But the weather in San Francisco for tomorrow, Sunday, January 18, 2026, is actually leaning toward the pleasant side of the spectrum.
Don't expect a heatwave.
The high is hitting exactly 62°F. That's basically the San Francisco "sweet spot" where you can survive in a light sweater but might regret a heavy puffer coat by 2:00 PM. The low is dipping to 51°F, so it’s going to be a bit crisp if you're heading out for an early morning coffee run or staying out late for dinner in the Mission.
The breakdown of your Sunday
Basically, it's a partly sunny situation. You'll see those classic patches of blue sky peeking through, though the clouds will definitely be hanging around to keep things from getting too bright.
The wind is surprisingly chill.
We're looking at a gentle 6 mph breeze coming from the north. In a city where the wind can sometimes feel like it's trying to push you off the sidewalk, 6 mph is nothing. It’s the kind of day where your hair stays mostly in place.
Will it rain?
Most likely not.
The daytime precipitation chance is a tiny 5%. By the time the sun goes down and we hit those "partly cloudy" night conditions, the chance of rain ticks up just a hair to 10%. Technically, it's "rain," but realistically, it's a "maybe you'll see a stray drop on your windshield" kind of vibe.
Humidity is sitting at 62%. It’s that standard coastal dampness that makes the air feel a bit heavier but keeps your skin from drying out like a raisin.
What to actually wear
Microclimates are real, people.
Even on a "partly sunny" day with a UV index of 2, the difference between standing in the sun at Dolores Park and walking through a shaded alley in Nob Hill is going to feel like ten degrees.
- Layers are non-negotiable. Start with a base tee.
- The middle layer. A flannel or a light hoodie works wonders.
- The shell. Since there’s a 10% chance of a night sprinkle, a light windbreaker isn't a bad idea, but you won't need the heavy-duty Gore-Tex.
The National Weather Service has been tracking a ridge of high pressure that’s been keeping things dry lately. While there’s talk of a "pattern change" coming later in the month that might bring back the real rain, Sunday is safely tucked into this dry window.
Practical steps for your day
If you're heading to the coast, maybe Ocean Beach or Lands End, keep in mind that the north wind, even at 6 mph, feels cooler near the water. The sun sets around 5:18 PM these days, and once it’s gone, that 51°F low will start to settle in fast.
👉 See also: Short Hair Messy Bun: Why You’re Doing It Wrong and How to Fix It
Check your local microclimate apps if you're moving between the Sunset and the Financial District. Usually, the "Avenues" will be a few degrees cooler and cloudier than the East side of the city.
Plan your outdoor activities for between 11:00 AM and 3:00 PM to catch that peak 62°F warmth. It’s a solid day for a hike or a stroll, just don't forget that it is still January, and the "partly sunny" description means the sun is going to be playing hide-and-seek all afternoon.