Honestly, if you're looking at the San Diego 10 day weather and expecting a frozen tundra or a tropical heatwave, you're basically going to be surprised either way. Most people think Southern California is just a perpetual 75-degree postcard. It’s not. Well, okay, sometimes it is, but January has its own weird, moody logic that can catch you off guard if you aren’t paying attention to the microclimates.
Right now, we are sitting in a bizarrely beautiful pocket of "winter." Today, January 14, 2026, it is a crisp 74°F with basically zero humidity (about 37%). If you walked outside in a parka, you’d look ridiculous. If you went out in just a swimsuit, you’d be shivering the second you hit the shade. That’s the San Diego tax.
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The San Diego 10 Day Weather Reality Check
Here is the deal. We are starting off this 10-day stretch with a bit of a "heat" spike. Tomorrow, Thursday, is looking even warmer with a high of 77°F. That’s incredible for mid-January. But look at the low: 56°F. That is a 21-degree swing. You basically have to dress for two different seasons in a single 24-hour period.
By Friday, the "cool down" starts, though calling it "cool" feels like a stretch to anyone living in the Midwest right now. We’re dropping to 69°F, and the clouds are going to start rolling in. This is that classic coastal transition.
What the next week actually looks like:
- The Sunny Peak: Wednesday and Thursday are your beach days. Highs in the mid-to-high 70s.
- The Gray Shift: From Saturday through next Tuesday (Jan 20), expect a lot of "mostly cloudy" or "partly sunny" days. Highs will hover right around 66°F to 70°F.
- The Slow Slide: By next Friday, Jan 23, we’re looking at a high of only 61°F. That’s when the locals start breaking out the heavy UGG boots and puffer jackets.
Why the "San Diego 10 Day Weather" is a Lie (Sorta)
I say it’s a lie because "San Diego" is a huge county. If you’re looking at the forecast for the airport (Lindbergh Field), you are getting the coastal vibe. But drive 20 minutes east to El Cajon or Santee? You can easily add 10 degrees to that high and subtract 5 from the low.
The National Weather Service is currently tracking some offshore flow—basically, the Santa Ana winds’ chill cousin. It keeps things dry. You’ll notice the humidity staying low (around 40-50%) for the first half of the week before the marine layer tries to make a comeback.
If you're planning to head to the mountains, like Julian, forget everything I just said. It’s a different world up there. But for the city proper, it's all about the "marine layer." That's the thick fog that rolls off the Pacific. It’s San Diego’s natural air conditioning. It’s why you can be sweating at 1:00 PM and reaching for a hoodie by 4:00 PM.
Survival Tips for the January Forecast
If you're visiting or just trying to plan your week, don't trust the "high" temperature alone. Look at the wind. Currently, we’ve got a light west wind at 4 mph, but it’s going to shift northwest and pick up a bit of speed toward the weekend. A 7 mph wind at 65 degrees feels a lot colder than you think when you're standing on the pier.
- Layers are your god. T-shirt, light sweater, medium jacket. Use them.
- Sunscreen is still mandatory. The UV index is hitting 3 today and tomorrow. It sounds low, but that California sun hits different when there isn't a cloud in sight.
- Check the surf. If you're a local, you know the swell is coming from the west/northwest. The water is roughly 58-60 degrees right now—definitely 4/3mm wetsuit territory.
The "rain" chances for the next 10 days are basically negligible. We’re seeing a 10% to 20% chance toward the end of next week, but in San Diego language, that usually means "it might mist on your windshield for three seconds."
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Actionable Next Steps
Check your specific zip code rather than just "San Diego" to get a real feel for the temperature swings. If you're inland, prepare for much colder nights (low 50s or high 40s) compared to the coast. Pack a windbreaker if you're doing any sunset activities, as the humidity jump from 37% to the predicted 73% by next Friday will make the air feel significantly "heavier" and cooler.