So, you’re looking at the oc weather 10 day forecast and wondering if it’s finally time to bust out the winter coat or if you’re stuck in that weird "shorts in the morning, shivering by 5 PM" cycle that defines Southern California winters. Honestly, January in Orange County is a bit of a mood. One day you're hitting 78°F and feeling like it's mid-July, and the next, you're checking the radar for a random rain cell.
Basically, right now is one of those peaks. If you stepped outside today, Sunday, January 18, you probably noticed it’s actually pretty hot. We’re sitting at a high of 78°F under sunny skies. It’s that dry, crisp heat that comes when the offshore winds decide to play nice. But don't let the afternoon sun fool you into leaving your windows open tonight; it’s going to drop all the way down to 49°F. That’s a nearly 30-degree swing. Classic OC.
The Mid-Week Shift You Need to Watch
Tomorrow, Monday, January 19, keeps the vibe going for MLK Day. You’ve got a high of 73°F and clear skies, which is basically perfect for a beach walk or a hike at Crystal Cove. But the real story starts on Wednesday.
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The high pressure that’s been keeping us toasty is starting to break down. By Wednesday, January 21, the clouds move in. We’re looking at a high of 69°F and, more importantly, a 20% chance of light rain at night. It isn't a "build an ark" kind of storm, but it's the start of a cooling trend that’s going to hang around for a while.
By Thursday, the high drops to 68°F and the humidity jumps up to 61%. There’s a 35% chance of rain during the day. If you’re planning on being outdoors, maybe keep a light shell in the car. It’s not just about the moisture; the "feel-like" temperature is going to be significantly lower than what we’re seeing this weekend.
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Breaking Down the 10-Day Numbers
Here is what the next week and a half actually looks like, no fluff:
- Sunday (Today): Sunny and a high of 78°F. Overnight low of 49°F.
- Monday: Sunny, staying warm at 73°F.
- Tuesday: Mostly cloudy. High 74°F, low 53°F.
- Wednesday: Cloudy with a high of 69°F. Watch for light rain (20%) at night.
- Thursday: Partly sunny but cooler. High 68°F with a 35% chance of rain.
- Friday: High of 65°F. This looks like the coldest day of the stretch.
- Saturday: Partly sunny, high 67°F.
- Next Sunday: We start to bounce back. High 72°F.
- Monday/Tuesday (Jan 26-27): Trending back into the mid-70s (73°F to 75°F).
It's a rollercoaster. You’re going from a 78-degree peak today down to a 65-degree low point on Friday, before the ridge builds back up and warms us up again for the end of the month.
Why the Forecast Keeps Changing
If you’ve lived here long enough, you know that the marine layer is a fickle beast. The National Weather Service out of San Diego has been tracking a weak Santa Ana flow that’s been keeping the fog at bay, but that’s ending. As the offshore flow weakens, that shallow marine layer is going to try to sneak back into the immediate coast.
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For those of you in Huntington or Newport, you’re going to see those "mostly cloudy" days turn into "dense morning fog" pretty quickly. Inland areas like Anaheim or Irvine will stay clearer, but everyone is going to feel that dip in temperature.
Honestly, the biggest misconception about January weather here is that it’s always "room temperature." It’s really not. We’re in the heart of our wet season, and while 2026 has been a bit erratic, the averages tell us we usually see about 2.5 inches of rain this month. We’re currently under those averages, which is why those 10% to 35% rain chances on Wednesday and Thursday are worth watching. They might not look like much, but they are the only real moisture we’ve got on the horizon.
What You Should Actually Do
Stop checking the app every hour. It’s going to be gorgeous through Tuesday, then it’s going to get "California cold" (which, let’s be real, is just 60s) for the rest of the week.
If you have a car, check your tire pressure. These 30-degree temperature swings between day and night are notorious for triggering those annoying low-pressure sensors. Also, if you’re planning on heading to the coast this weekend, go before Wednesday. The water temp is hanging around 59°F, which is bracing, to say the least, but the sunshine makes it bearable. Once those clouds hit on Wednesday, the beach is going to feel pretty dismal until next Sunday.
Stay prepared for that Thursday rain—35% isn't a guarantee, but it's enough to ruin a car wash. Hold off on the wax job until next Monday when things clear up again.