FirstAlerts

Dense Fog Advisory Issued for Sioux, O'Brien, Plymouth, and Cherokee Counties Until 9 AM Wednesday

The National Weather Service has issued a Dense Fog Advisory for parts of northwest Iowa, effective until 9 AM CDT Wednesday.

3 reports on this incident · first at Sep 9, 2026, 12:48 a.m. ET

By AI ReporterWritten Sep 9, 2026, 12:52 a.m. ET
The National Weather Service in Sioux Falls has issued a for Sioux, O'Brien, Plymouth, and Cherokee counties in northwest Iowa. The is in effect from 11:39 PM CDT Tuesday until 9 AM CDT Wednesday, September 9, 2026. Visibility is expected to drop below one half mile in dense fog, which could make driving conditions hazardous. The covers the cities of Hartley, Cherokee, Hull, Sheldon, Hawarden, Sioux Center, Le Mars, Orange City, Sanborn, and Rock Valley.

Earlier reports

  1. Sep 9, 2026, 12:52 a.m. ET

    Dense Fog Advisory for Sioux, O'Brien, Plymouth, Cherokee Until 9 AM Wednesday

    The National Weather Service Sioux Falls SD says that low visibility could make driving conditions hazardous in Cherokee, O'Brien, Plymouth, and Sioux Counties. The advisory is in effect until 9 AM CDT Wednesday, September 9, 2026.

    The advisory, issued at 11:39 PM CDT Tuesday, warns of visibility below one half a mile in dense fog. The affected areas include Hartley, Cherokee, Hull, Sheldon, Hawarden, Sioux Center, Le Mars, Orange City, Sanborn, and Rock Valley.

    If driving, the Weather Service advises slowing down, using headlights, and leaving plenty of distance ahead of you.

  2. Sep 9, 2026, 12:48 a.m. ETFirst report

    Dense Fog Advisory Issued for Sioux, O'Brien, Plymouth, and Cherokee Counties Until 9 AM Wednesday

    The National Weather Service in Sioux Falls, South Dakota, issued a Dense Fog Advisory at 11:39 PM CDT Tuesday, September 8, 2026, in effect until 9 AM CDT Wednesday, September 9, 2026. The advisory covers Cherokee, O'Brien, Plymouth, and Sioux Counties in northwest Iowa, including the cities of Hartley, Cherokee, Hull, Sheldon, Hawarden, Sioux Center, Le Mars, Orange City, Sanborn, and Rock Valley.

    According to the advisory, visibility could drop below half a mile in dense fog, making driving conditions hazardous. The NWS advises drivers to slow down, use headlights, and leave plenty of distance ahead of them.

Was this report accurate and useful?

Sources

Revision history

  1. Version 19 Sept 2026, 04:52current

    First published.

  2. Version 19 Sept 2026, 04:48current

    First published.

  3. Version 19 Sept 2026, 04:52current

    First published.

How we work

This site models an investigative reporter rather than a wire desk. The aim is the most complete, accurate and timely account we can assemble — all three, not a trade between them. Reports go out within minutes of the coverage they are built from, carrying context a newsroom would otherwise need a day and a records request to gather: what has happened at this place before, what the operator’s record is, which aircraft it actually was.

Reports are built from primary sources — accident and court records, official registries, weather observations, agency statements — and from reputable news organisations, each named where their reporting is used. Facts are extracted before anything is written, and every one must be supported by a quotation found in the source itself; the model that writes the report is given only those verified facts and never sees the article, so it cannot introduce a detail no source stated.

Where sources disagree we publish the disagreement, attributed, rather than picking a figure. Where a fact comes from a record rather than a reporter, we say so, and the language matches: an instrument reading is never described as something anyone confirmed. Some things are deliberately withheld — a suspect is not named until an agency names them on the record, victims until families or officials release them — and corrections appear as visible revisions, never as silent edits.

None of that makes a report true. A quotation check proves a source said something, not that it was right, and an automated system can be confidently wrong in ways the checks do not catch. If something here is wrong, the feedback above is how it gets found. The full methodology, including what we refuse to publish.