Right now, the current temperature San Diego is sitting at a crisp 60°F. If you’re standing outside near the Gaslamp or catching the breeze down at the Embarcadero, you’ll notice it’s a clear Sunday night. The wind is barely a whisper—just 3 mph coming from the north—and the humidity is hovering at 60%. Honestly, it’s that classic January vibe where the air feels thin and cool, but not exactly "winter" by anyone else's standards.
Earlier today, things were quite a bit toastier. We hit a high of 75°F under a perfectly sunny sky. That's the thing about San Diego; the "average" high for mid-January is usually closer to 65°F or 66°F, according to long-term data from the National Weather Service. Pushing into the mid-70s means we’re definitely enjoying a warmer-than-usual spell today.
Most people think San Diego is just "70 degrees and sunny" every single day of the year.
It's a nice thought. It's also kinda wrong.
The Microclimate Reality
The city is basically a giant collection of microclimates. You can drive five miles and watch your dashboard thermometer jump or dive by ten degrees. This is largely due to the "marine layer"—that thick blanket of cool, moist air that the Pacific Ocean pushes onto the coast.
While the downtown area might be 60°F tonight, go ten miles inland to El Cajon or Santee, and you’ll likely find it a few degrees cooler. The ocean acts like a giant thermostat. It keeps the coast from getting too hot in the summer and too cold in the winter. In January, the water temperature is usually around 58°F to 60°F. Since the air over the water stays relatively stable, the coastal neighborhoods rarely see the wild swings that the inland valleys do.
Tonight’s low is expected to hit 54°F. That’s pretty standard for a January night. If you’re planning on being out late, you’ll want a light jacket. Don't be that tourist in a tank top shivering at a rooftop bar just because you heard it "never gets cold" here.
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Why the Ocean Controls Everything
If you’ve ever wondered why the current temperature San Diego feels so different from, say, Phoenix or even Los Angeles, look at the water. The Pacific current flows from north to south, bringing cold water down from Alaska. This is why you need a 4/3mm wetsuit if you’re surfing at La Jolla Shores in January.
Unlike the East Coast, where the Gulf Stream brings warm water up from the tropics, our water stays chilly. This creates a "heat sink" effect. Even on a day like today where we hit 75°F, as soon as that sun dips behind the horizon, the temperature drops fast.
Looking Back and Moving Forward
Historically, San Diego has seen some weird stuff in January. The record low for the month was a bone-chilling 25°F back in 1913. On the flip side, it’s hit 88°F before. We aren't anywhere near those extremes tonight, but it’s a good reminder that the "perfect" weather is more of a range than a rule.
If you're tracking the current temperature San Diego to plan your week, here is what you actually need to know:
- Coastal Stability: If you’re within 3 miles of the beach, expect very little variation.
- Inland Swings: If you’re heading toward the mountains, expect it to be 5-10 degrees warmer during the day and significantly colder at night.
- Sun Intensity: Even when it’s 60°F, the UV index during the day can be sneaky. Today it was only a 2, but that’s enough to catch a light burn if you’re fair-skinned and out for hours.
Basically, if you're here right now, enjoy the clear skies. The chance of rain is 0% for the rest of the night. Tomorrow looks like it’ll be another winner, though maybe a few degrees cooler than today's 75°F peak.
Next Steps for Your San Diego Day:
- Layer up: If you're heading out for a late-night walk, a medium-weight sweater is the move.
- Check the surf: With the wind coming from the north at 3 mph, conditions are relatively glassy, though the water remains in that 59°F-60°F range.
- Monitor the Inland/Coastal Gap: If you are driving east toward La Mesa or El Cajon tomorrow, prepare for a 5-8 degree jump from the coastal readings.