If you’ve spent more than five minutes in the Miami Valley during mid-January, you know the drill. One second you’re scraping a thin sheet of "Dayton glaze" off your windshield, and the next, you’re wondering if you actually need that heavy parka or if a stout hoodie will do. Honestly, the Dayton OH extended forecast for the back half of January 2026 is leaning hard into that classic, unpredictable Ohio rhythm.
Right now, as of Saturday, January 17, we’re sitting at a crisp 31°F. It’s mostly sunny, which is a nice break from the "gray blanket" that usually settles over the city this time of year. But don’t let that little bit of blue sky fool you. The wind is coming out of the west at 14 mph, making it feel more like 21°F. If you’re heading out to the Oregon District or just grabbing groceries, that wind chill is the real story today.
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The Week Ahead: Bitter Cold is Coming
Basically, we’re looking at a sliding scale of "cold" to "painfully cold." Today’s high is expected to top out at 33°F with clouds moving in. We might see some scattered snow showers or flurries this afternoon—the National Weather Service out of Wilmington has been keeping a close eye on a secondary cold front pushing through from the west.
Here is the vibe for the next few days:
- Sunday, Jan 18: High of 24°F, low of 14°F. Expect flurries. It’s that dry, powdery stuff that doesn’t stick well but makes the roads just greasy enough to be annoying.
- Monday, Jan 19: This is the one to watch. The high is only 21°F, but the low crashes down to 6°F. With wind gusts potentially hitting 30-35 mph, we’re talking about wind chills well below zero.
- Tuesday, Jan 20: Mostly sunny but don't get excited. It stays freezing with a high of 22°F.
The big takeaway? Monday and Tuesday are going to be the "stay inside and make chili" days. The lack of solar warming on Monday means those temperatures aren't going anywhere once they drop.
Why Dayton Weather is Such a Mess
People always blame the lake, but we’re a bit far south for true lake-effect snow like Cleveland gets. Instead, we get the "Miami Valley Trash Compactor." Because Dayton sits in a bit of a bowl—where the Mad River, Stillwater, and Wolf Creek meet the Great Miami—cold air likes to settle and just... hang out.
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Meteorologists often point to the "I-70 Divide." It’s a real thing. Often, you’ll see rain in Miamisburg while Vandalia is getting hammered with sleet. For this extended outlook, the models are showing a firm turn toward colder trends for the Eastern U.S., and Dayton is right on the edge of that transition zone.
Looking Toward February
If you’re checking the Dayton OH extended forecast to see when the thaw starts, you might have to wait a bit. The Farmers' Almanac and regional long-range outlooks suggest that while February might have some "very warm" periods between the 6th and 17th, the first week of February looks brutal. We’re talking heavy snow potential for the Ohio Valley.
For the remainder of January, expect the mercury to hover around 32°F, which is actually about two degrees below our historical average. Precipitation is looking a bit lower than normal too, so while it’ll be cold, we might skip the massive snowdrifts for a while.
Preparing for the Deep Freeze
Since we’re staring down some single-digit lows early next week, it’s time for the boring-but-necessary adult stuff.
- Check your tires. Cold air makes tire pressure drop faster than a Bengals lead in the fourth quarter.
- Drip those faucets. If you’re in one of those charming older homes in South Park or St. Anne’s Hill, your pipes are vulnerable when it hits 6°F.
- Livestock and Pets. If you’re out in the more rural parts of Montgomery or Greene County, get the extra bedding out now.
The humidity is currently around 46%, but that’s going to climb as the snow flurries move in tonight. Higher humidity makes the cold feel "wetter" and more bone-chilling. Layers are your best friend—and maybe a remote starter if you’re fancy.
Practical Next Steps:
Check your car's antifreeze levels and battery strength today before the sub-zero wind chills arrive on Monday night. If your battery is more than three years old, a 6°F night is exactly when it will decide to give up the ghost. Also, clear any debris from your furnace exhaust vents to avoid carbon monoxide buildup during the extended run-times expected this week.