If you’re living in or passing through northern Boone County, you’ve probably realized that weather in Poplar Grove isn't just a background detail—it's a lifestyle. Honestly, one day you’re enjoying a crisp 70-degree afternoon in May, and the next, you’re bracing for a January deep freeze that feels like it’s coming straight from the Arctic.
Right now, as of January 15, 2026, we’re sitting in the thick of a classic Illinois winter. The temperature is hovering at a chilly 22°F, but with the wind coming out of the south at 10 mph, it actually feels like 11°F. It’s that biting, "don't-forget-your-gloves" kind of cold. Tonight, the mercury is expected to drop to 10°F, with snow showers likely.
Why Poplar Grove Weather Is So Unpredictable
Basically, we live in a "Humid Continental" zone.
That’s a fancy way of saying we get the full range of emotions from mother nature. We get the hot, sticky summers where the high hits 82°F in July, and then we get the "freezing, windy, and snowy" winters that we’re currently enduring.
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Kinda wild when you think about it.
The Winter Reality
January is, without question, the toughest month here. The average high is only 28°F, and the lows frequently dip to 12°F or 15°F. If you look at the 10-day forecast starting today, it’s a rollercoaster of "snow showers" and "mostly cloudy" days. Tomorrow, January 16, might reach a high of 34°F, but don’t get too excited—it’s bringing a 35% chance of snow along with it.
By next Monday, January 19, the high is projected to be a measly 4°F. That’s not a typo.
- Extreme Cold: Temperatures can occasionally drop below -5°F.
- Persistent Clouds: In December and January, the sky is overcast about 58% of the time.
- Wind Chill: Because the terrain is relatively flat, the wind really whips through here, making 20 degrees feel like zero.
The Seasonal Shift: When it Actually Gets Nice
If you’re tired of the snow, there’s a light at the end of the tunnel. The "warm season" in Poplar Grove officially kicks off around May 21 and lasts until September 20. During this window, the daily high usually stays above 72°F.
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July is the peak. It’s the hottest month, with an average high of 82°F and a low of 63°F. It’s perfect for the Boone County Fair or just hanging out at the local parks, though it does get wet. June is actually the wettest month, averaging about 5.41 inches of rain.
Sun and Clouds
September is secretly the best month for weather in Poplar Grove. The sky is clear or mostly clear about 64% of the time. The humidity drops, the bugs clear out, and you get those perfect 74°F days that make you forget the -5°F blizzard from three months prior.
Rare and Extreme Events You Should Know About
Poplar Grove has seen some serious drama. On January 7, 2008, an EF-3 tornado ripped through the area, which is incredibly rare for January. It tracked from Poplar Grove toward Harvard, causing major damage to iconic spots like Edward’s Apple Orchard. It was a stark reminder that even in the dead of winter, the weather here can pull a fast one on you.
We also deal with:
- Ice Storms: Late February is notorious for these, turning Highway 76 into a skating rink.
- Flash Floods: Heavy August rains can dump 5+ inches in a single day.
- Snow Squalls: These can drop visibility to near zero in seconds, which is why the local school districts (North Boone CUSD 200) are so fast on the "Snow Day" trigger.
Survival Tips for the 10-Day Stretch
If you're looking at the upcoming forecast, you need a plan. With highs staying mostly in the teens and 20s for the next week, and a significant dip to 4°F on Monday, your home and car need to be ready.
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Check your tire pressure. Cold air makes the pressure drop, and the "low tire" light is basically the official dashboard icon of Poplar Grove in January. Drip your faucets if your home is older or has pipes on exterior walls, especially when we hit that -1°F low on Monday night.
Watch the wind direction. Most of our upcoming weather is coming from the West/Southwest. If you’re driving on east-west roads, be prepared for significant crosswinds, especially near open farm fields.
Prepare for snow showers. We have a 40% chance of snow tonight and 35% tomorrow. It’s not a blizzard, but it’s enough to make the morning commute greasy. Keep a bag of sand or salt in the trunk—you’ve likely seen someone stuck in a drift near the high school, and it’s never a fun time.
Stay warm, keep the de-icer handy, and remember: it’ll be 80 degrees before you know it. Kinda.