Right now, if you stepped outside in San Diego, you’d feel a crisp 54°F. It’s nighttime, specifically the early hours of Saturday, January 17, 2026, and the sky is draped in a thick layer of clouds. Honestly, if you’re coming from the Midwest, this probably feels like a balmy spring evening. But for locals? We’re currently digging out the "heavy" hoodies because the humidity is sitting at a damp 90%.
The wind is barely a whisper, just 2 mph coming from the northeast. It's that quiet, still kind of cold.
But here is the thing about San Diego: the "current temp" is a total liar. By the time the sun actually gets some work done later today, we’re looking at a high of 76°F. That is a massive 22-degree jump from the overnight low of 49°F. If you don’t dress in layers here, you’re basically volunteering to be miserable for half the day.
The San Diego Temperature Reality Check
People think San Diego is just 72 degrees and sunny every single day of the year. I wish. While we do get about 260+ "pleasant" days, January is actually our "winter," even if that sounds like a joke to someone from Chicago.
Today, Saturday, January 17, the forecast is calling for partly sunny skies during the day. Don't let those morning clouds fool you; the UV index will hit a 2, so you still might want a bit of SPF if you’re hitting the Balboa Park trails. The wind will pick up a bit too, reaching about 8 mph from the north.
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Today’s Vital Stats at a Glance
- High: 76°F
- Low: 49°F
- Condition: Partly sunny day, mostly cloudy night
- Rain Chance: 10% (Basically, don't worry about it)
- Humidity: Dropping to around 37% during the day
Why the Neighborhood Matters More Than the App
You can’t just ask "whats the temp in san diego" and expect one answer. This city is a mess of microclimates. You’ve got the coastal chill, the inland heat, and the mountain transitions.
If you are standing on the sand at La Jolla Shores, it might be a breezy 65 degrees. But if you drive just 15 minutes east to Santee or El Cajon? It could easily be 80 degrees. The ocean acts like a giant air conditioner. The further you get from it, the more the "AC" fails.
In January, the marine layer—that thick "June Gloom" style fog—can actually show up early. It keeps the coast cool and gray while the inland valleys are baking under clear skies. If you're planning a trip to the San Diego Zoo Safari Park in Escondido, expect it to be much warmer than the original Zoo in Balboa Park.
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Pack Like a Pro (Because You'll Need To)
Since the temperature swings so wildly from 49°F at night to 76°F in the afternoon, your suitcase needs to be strategic.
- The Base Layer: A t-shirt or light tank.
- The Mid Layer: A flannel or a light sweater.
- The Shell: A denim jacket or a light windbreaker for the evening breeze.
- The "Locals" Special: Flip-flops are acceptable year-round, but maybe bring socks for the 49-degree mornings.
The humidity today is starting high but will dry out significantly. By the time that north wind hits 8 mph this afternoon, it’ll feel like perfect walking weather.
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Actionable Next Steps for Your Saturday
If you're in town today, capitalize on that 76°F high. The morning might start mostly cloudy, but it’s going to clear up into a beautiful afternoon.
- Morning (54°F - 60°F): Perfect time for coffee in Little Italy. It’s chilly, so the outdoor heaters will be on.
- Midday (70°F - 76°F): Head to the coast. The 10% rain chance is negligible, so a walk along the Sunset Cliffs is a safe bet.
- Evening (Back down to 50s): The temp drops fast once the sun sets. If you have dinner reservations in the Gaslamp, bring that jacket. You'll see locals in parkas—ignore them, they're just sensitive to the "cold."
Check the sky around 4:00 PM. If the clouds stay thin, the transition from partly sunny to mostly cloudy usually makes for a pretty killer purple sunset over the Pacific.