Honestly, if you grew up in Southern California, you’ve probably spent years telling out-of-state relatives that we "don't really have seasons." We usually just swap our flip-flops for slightly sturdier flip-flops once November hits. But this year is feeling a little different. While the 10 day forecast Costa Mesa residents are staring at right now looks like a typical Mediterranean dream on paper, there's a weird tension between the lingering La Niña and some surprisingly warm spikes.
It’s confusing. One day you’re looking at 76°F and wondering if it’s too early for the beach, and the next, you’re digging out a puffer jacket because the humidity jumped to 68% and that "mildly cool" ocean breeze suddenly has some real teeth.
The Breakdown: What’s Actually Happening Over the Next 10 Days
Right now, we are in a bit of a weather tug-of-war. Today, Friday, January 16, we’re seeing a high of 76°F with a very dry 47% humidity. It feels like spring. But don't let the sun fool you into thinking the "winter" part of the year is over. By tonight, the clouds are rolling in, and we’re dropping down to 53°F.
Here is the weird part: Saturday is going to stay warm at 76°F, but the clouds are sticking around. It’s that "mostly cloudy" but still hot vibe that makes choosing an outfit for a walk around the CAMP or the Lab basically impossible.
As we move into next week, things start to "cool off" (if you can call it that). By Monday and Tuesday, we’re settling into the high 60s and low 70s. The humidity is going to hover around 47% to 49%, which is pretty much the sweet spot for Orange County comfort. However, keep an eye on Thursday, January 22. We’re looking at a 20% chance of rain with a high of only 66°F. It’s not a deluge, but in a year where we’ve already had heavy rains extend events like Winter Fest OC at the Fairgrounds, we’ve learned not to ignore even a small percentage.
Why the 10 Day Forecast Costa Mesa is So Unpredictable This Year
We’re currently in a "La Niña Advisory" phase. Usually, for us in the Southwest, La Niña means "get ready for a drought, it’s going to be dry and warm." But as the folks at NOAA and the Climate Prediction Center have been pointing out, this particular La Niña is being a bit of a rebel.
Earlier this month, heavy rains actually forced Winter Fest OC to extend its dates because the "dry" winter just didn't show up when it was supposed to. Scientists are seeing a 75% chance that we transition to "ENSO-neutral" conditions (the middle ground between El Niño and La Niña) between now and March.
Basically, the atmosphere is acting like it’s already spring, while the ocean is still trying to hold onto its cold La Niña patterns. This creates that specific Costa Mesa microclimate where you get:
- Northwest winds at about 5-6 mph (enough to make the shade feel cold).
- UV indices around 3 (low, but enough to catch a burn if you're outside all afternoon).
- Drastic 20-degree drops between 2:00 PM and 8:00 PM.
How to Actually Live Through This Forecast
If you're planning your week, the best days for outdoor stuff are definitely Monday and Tuesday. Monday, January 19, is looking "mostly sunny" with a high of 69°F and a low of 56°F. It’s the perfect weather for a long morning at the Upper Newport Bay Nature Preserve or just grabbing a coffee and sitting outside at Sidecar Doughnuts.
By the end of the 10-day window, around Sunday, January 25, we’re looking at 67°F and partly sunny skies. It’s consistent, but it’s a far cry from the mid-70s we’re enjoying this weekend.
Actionable Winter Survival (SoCal Style)
Since the 10 day forecast Costa Mesa is showing a mix of high heat and potential dampness, you need a strategy.
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- The "Three-Layer" Rule: Forget heavy coats. You need a base tee, a light hoodie, and a windbreaker. Those 5 mph northwest winds are deceptive when the sun goes behind a cloud.
- Thursday is the "Indoor Day": With the highest chance of rain (20%) and the lowest temperatures of the week (66°F), Thursday, January 22, is the day to hit South Coast Plaza. It’s climate-controlled and, honestly, a better vibe when it’s gloomy out.
- Hydrate More Than You Think: Even though it's not "hot," the humidity is dropping to 33% on Saturday. That dry air will sneak up on you.
- Check the Fairgrounds Schedule: Since weather extensions are a thing this year, always double-check if local outdoor events have added days to make up for those earlier rains.
The biggest takeaway? Don't trust the morning sun. In Costa Mesa, the weather isn't a state of being; it's a moving target. Enjoy the 76°F days while they last, because the 60s are coming back for us next week.
Next Steps:
Go ahead and check your tire pressure today. With the temperature swings from 76°F down to 53°F, your "low pressure" light is almost guaranteed to pop on this weekend as the air in your tires fluctuates.