You’ve seen the postcards. Always sunny, always 75 degrees, people surfing in January without a care in the world. Honestly? That’s mostly a marketing myth, but the reality is actually better if you know how to play it.
The 7 day san diego weather forecast right now is a perfect example of why this city is a "bring a jacket" kind of paradise. If you’re looking at the week of January 15, 2026, you’re seeing a classic transition. We’re coming off a weirdly hot Thursday where it hit 80°F—which is basically a "Santa Ana" event where the desert air pushes back the ocean—but things are about to get much more "San Diego normal."
Basically, don't trust the first number you see on your phone.
The San Diego Temperature Rollercoaster
Tomorrow, Friday, January 16, we’re dropping to a high of 71°F. By next Thursday, it’ll be 65°F. That’s a 15-degree swing in a week. For locals, a 65-degree day is basically an arctic blast. For someone visiting from Chicago or New York? It’s a dream.
The trick is the low. Every single night this week, the temperature is hovering right around 49°F to 52°F.
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That’s the "San Diego Tax." You pay for the sun during the day, but as soon as that sun dips behind the Pacific at 5:05 PM, the temperature craters. If you’re at the San Diego Zoo or walking around Balboa Park, you’ll see tourists in shorts shivering the second the shadows get long. Don't be that person.
The Real 7-Day Outlook (Jan 15 - Jan 22, 2026)
Here is the raw data from the current window. No fluff, just the numbers:
- Friday (Jan 16): Partly sunny. High of 71°F, Low of 49°F. Humidity is sitting at 53%.
- Saturday (Jan 17): A bit warmer at 75°F. The humidity drops to 34%, which means it’ll feel crisp.
- Sunday (Jan 18): 74°F and partly sunny. Great for the beach, but the water is currently in the low 60s. Wear a wetsuit or stay on the sand.
- Monday (Jan 19): 70°F. The clouds start rolling in a bit more.
- Tuesday (Jan 20): 69°F. Mostly sunny, but the "marine layer" (that thick coastal fog) might stick around a little longer in the morning.
- Wednesday (Jan 21): 67°F. A 10% chance of rain at night. It’s not a deluge, just a "San Diego car wash"—enough to make the roads slick but not enough to cancel your plans.
- Thursday (Jan 22): 65°F. Mostly cloudy. This is the coolest day of the stretch.
The Microclimate Myth
The biggest mistake people make with 7 day san diego weather is assuming the airport forecast (which is where most apps get their data) applies to the whole county. It doesn't. Not even close.
San Diego has 19 distinct microclimates. If the forecast says 70°F for "San Diego," that might mean:
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- 64°F in La Jolla (because the ocean acts like a giant air conditioner).
- 78°F in El Cajon (just 15 miles inland).
- 55°F in Alpine (if you start heading toward the mountains).
If you’re planning a trip to the Safari Park in Escondido, add 5 to 10 degrees to whatever your phone tells you. If you’re heading to the Torrey Pines Gliderport to watch the sunset, subtract 5 and add a wind-chill factor. The northwest winds this week are steady at about 5 to 8 mph, which feels surprisingly biting when you’re standing on a cliff over the water.
Why 10% Rain Actually Matters
You’ll see "10% chance of rain" on Saturday night or next Wednesday. In Seattle, that’s a joke. In San Diego, it usually means the marine layer is getting "deep."
The marine layer is a temperature inversion. Cool air from the Pacific gets trapped under a lid of warm air. Sometimes it just stays as fog, but if it gets thick enough, it turns into "mist-rain" that doesn't show up on radar but will definitely ruin a suede jacket.
January is historically one of our wettest months, averaging about 2 inches of rain. But it usually comes in one or two big storms rather than constant drizzle. This week looks dry, but the humidity is spiking to 97% tonight, which means heavy dew and "wet" air in the mornings.
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Actionable Survival Tips for This Week
- The 3-Layer Rule: You need a t-shirt for 1:00 PM, a light hoodie for 4:00 PM, and a real jacket if you’re staying out for dinner.
- Sunscreen is a Trap: The UV index is only 2 or 3 this week, but the reflection off the ocean is real. People get burned at La Jolla Cove in January all the time because they think the "cool" breeze protects them. It doesn't.
- Whale Watching Alert: This is peak migration season. The 71°F Friday forecast is perfect for a boat tour, but remember: the temperature on the water is always 10 degrees colder than on land.
- Traffic and "Rain": If it does sprinkle on Wednesday night, be careful. San Diego roads accumulate oil for months during the dry season. The first 15 minutes of a light rain turn the freeways into ice rinks. Locals... well, we don't handle rain well.
What to Do Based on This Forecast
Since the 7 day san diego weather is trending cooler toward the end of the week, front-load your outdoor stuff.
Hit the San Diego Zoo on Friday or Saturday while it’s still in the mid-70s. Save the museums at Balboa Park (like the Fleet Science Center or the Air & Space Museum) for next Thursday when it’s 65°F and cloudy. If you’re a golfer, Sunday at Torrey Pines looks like the "Goldilocks" day—sunny enough for views but cool enough that you won't melt on the back nine.
Honestly, even a "bad" weather day here is better than a good day in most other places. Just don't let the 80-degree spikes fool you into leaving your sweater at home.
Next Steps:
Check the "Marine Layer" report specifically if you are staying in La Jolla or Del Mar, as coastal fog can linger until noon even on "sunny" days. If you're heading inland to the mountains, verify if frost warnings are in effect for the 49°F nights.