If you’re stepping outside in Fontana today, you’ve probably noticed something a bit odd for January. It’s warm. Like, weirdly warm. While the rest of the country is fighting off the remnants of a "Polar Vortex" or shoveling snow in the Northeast, we’re sitting here in the Inland Empire with temperatures pushing $80^{\circ}\text{F}$. Honestly, it feels more like a May afternoon than a winter morning.
But there’s a catch. There is always a catch when it comes to what is the weather in fontana california.
Right now, as of mid-January 2026, we are staring down a classic Santa Ana wind event. If you’re new to the area, you’ll learn pretty quickly that the "Windy City" title shouldn't just belong to Chicago. Fontana is basically a wind tunnel. Because we are sitting right at the mouth of the Cajon Pass, when high pressure builds over the Great Basin in Nevada and Utah, that air has nowhere to go but down through the mountains and straight into our backyard.
It’s bone-dry. The humidity has plummeted to around 16%, which is why your skin feels like parchment and your allergies are probably screaming.
The Reality of Fontana’s "Winter"
So, what should you actually expect? If you're looking at the 7-day forecast, it’s a lot of sun. We are seeing highs between $76^{\circ}\text{F}$ and $80^{\circ}\text{F}$ through the weekend. It’s beautiful, sure, but it’s also a little deceptive.
👉 See also: 3000 Yen to USD: What Your Money Actually Buys in Japan Today
The National Weather Service has issued wind advisories for a reason. North winds are sustained at 15 to 25 mph, but the gusts are hitting 35 mph or higher in the more exposed parts of town. You’ll see "patchy blowing dust" on the reports—that’s just code for "hold onto your steering wheel when you’re driving the 210 or the 15 freeway."
A Quick Breakdown of the Current Week:
- Wednesday & Thursday: Clear skies, peak heat around $80^{\circ}\text{F}-81^{\circ}\text{F}$.
- Friday: A slight dip to $77^{\circ}\text{F}$, but still very sunny.
- The Weekend: Holding steady in the high 70s. Perfect for a hike, maybe, but keep an eye on fire risks.
The real shift doesn't happen until late next week. Around January 21st or 22nd, the "January Thaw" we’re currently enjoying is supposed to break. Temperatures will likely drop back into the 60s, and there’s a genuine 25% chance of actual rain by Friday, January 23rd.
What Most People Get Wrong About Fontana’s Climate
People think Southern California is just "sunny and 72" all year. Locals know better. Fontana has what experts call a Mediterranean climate, but with a heavy dose of high-desert influence.
In the summer, it’s a furnace. We’re talking August highs that regularly average $94^{\circ}\text{F}$ but can easily spike to $103^{\circ}\text{F}$. It’s arid, clear, and relentlessly hot. But the winters? They’re long and cool, with lows often dipping into the low 40s. If you’re out at the Fontana Speedway or walking around Victoria Gardens at night in December, you’re going to want a real jacket.
✨ Don't miss: The Eloise Room at The Plaza: What Most People Get Wrong
Then there are the Santa Anas. These aren't just "breezes." When the air compresses as it drops from the high desert down to the valley floor, it heats up. That’s why it’s $80^{\circ}\text{F}$ today while the desert is significantly colder. This "adiabatic heating" is a fancy way of saying the air gets squeezed and toasted on its way down to us.
Fire Risk and Safety in 2026
We have to talk about the elephant in the room: wildfires. Just last year, in January 2025, Southern California saw devastating fires fueled by these exact same wind conditions. When the humidity drops below 10%—which it can do during a bad Santa Ana—the brush becomes "explosive fuel," according to ecologists like Jon Keeley.
Even though it’s "winter," the fire season in Fontana never really ends. If you’re living near the foothills, you’ve basically got to be ready to move at a moment's notice when the winds pick up.
Surviving the Fontana Wind Tunnel
If you're planning your day, here’s the ground truth on how to handle what is the weather in fontana california right now.
🔗 Read more: TSA PreCheck Look Up Number: What Most People Get Wrong
First, check your yard. Seriously. These 35-mph gusts will take a patio umbrella or a loose trash can lid and turn it into a projectile. Secure anything that isn't bolted down.
Second, the "commuter struggle" is real. If you’re driving a high-profile vehicle—like a van or a lifted truck—be incredibly careful on the I-15 through the Cajon Pass. The crosswinds there can be terrifying. It’s not uncommon to see semi-trucks pulled over waiting for the gusts to die down.
Third, hydrate. It sounds basic, but when the humidity is this low, you lose moisture just by breathing. You won't feel "sweaty" because the wind evaporates everything instantly, but you'll get a headache before you realize you’re dehydrated.
Actionable Next Steps for Fontana Residents:
- Check your tires: Drastic temperature swings (from $50^{\circ}\text{F}$ at night to $80^{\circ}\text{F}$ during the day) can mess with your tire pressure.
- Prune your trees: If you have dead limbs on your Eucalyptus or Pine trees, get them trimmed now before the next 60-mph gust snaps them onto your roof.
- Dust-proof your home: Keep the windows shut during the day. The blowing dust isn't just an outdoor problem; it’ll coat your furniture in a fine layer of silt within hours.
- Update your emergency kit: Ensure you have a "go-bag" ready if you live in a high-fire-risk zone, especially with the current dry spell.
While the heat is a nice break from the winter gloom, don't let it fool you. Fontana's weather is a game of extremes. Stay hydrated, watch the wind advisories, and enjoy the sun while it lasts—the rain is likely coming back before the month is out.