If you’re planning a late-night drive or early morning commute along the I-80 corridor in Illinois, you might want to rethink your plans. A Dense Fog Advisory has just been issued that could turn your routine drive into a dangerous journey. From midnight until 9:00 AM on Thursday, parts of Illinois will face extremely low visibility, causing serious risks for drivers on one of the state’s busiest highways.
Fog Advisory in Effect: What’s Happening in Illinois Tonight?
The National Weather Service has sounded the alarm: dense fog is expected to roll in across northern and central Illinois, especially along the I-80 corridor. This type of fog isn’t your usual morning mist — it’s thick, blinding, and potentially hazardous, especially for anyone driving at night or during the early morning rush hour.
The advisory starts at 12:00 AM and continues through 9:00 AM Thursday, during which visibility may drop to less than a quarter of a mile in some spots. For context, that’s barely enough space to see the tail lights of the car in front of you.
Where Exactly Will This Fog Hit?
The fog is expected to hit areas stretching along and near I-80, impacting both city and rural zones, including:
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Joliet
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Morris
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Ottawa
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LaSalle-Peru
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Geneseo
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And smaller communities and open stretches in between
Drivers in these areas should be especially cautious, particularly around bridges, overpasses, and low-lying fields, where fog tends to settle even more densely.
Why Is This Fog So Dangerous?
Fog like this forms when the air cools rapidly at night, especially when there’s plenty of moisture near the ground. With skies expected to be clear and winds calm, it’s the perfect setup for ground-level fog to form and stick around until mid-morning.
This isn’t just a visibility problem. Thick fog confuses depth perception, reduces contrast, and can make road lines harder to see — even for experienced drivers. Add high speeds on I-80 to the mix, and you have a recipe for serious accidents if drivers aren’t extra careful.
Safety Tips: How to Drive in Dense Fog
Weather experts and traffic officials urge all drivers to follow these safety tips during the advisory window:
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Use low-beam headlights only – high beams reflect off the fog and make things worse
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Slow down and maintain a safe distance from the car ahead
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Avoid cruise control – it removes your ability to respond quickly
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Be alert for brake lights and stop signs
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If visibility gets too bad, pull over in a safe place with hazard lights on
Better yet, if your travel isn’t urgent, wait until the fog clears. Visibility usually improves as the sun rises and temperatures increase.
When Will It Clear Up?
Forecasters expect the fog to begin lifting around 8:00 to 9:00 AM, but some areas — especially valleys and farmlands — may continue to see patchy fog even later into the morning.
Commuters heading into Chicago or other urban areas from the I-80 corridor should expect slower travel times, and possibly delays due to reduced visibility.
Final Word: Stay Safe, Stay Informed
This may seem like a regular fog alert, but weather like this has caused major pile-ups and fatal accidents in the past. It’s always better to be a little late than to risk a dangerous drive.
Stay connected to local weather updates, use navigation apps with real-time traffic alerts, and if you can, postpone non-essential travel until conditions improve.
