Colorado, 2026

Dense Fog in Colorado, March 4, 2026

March 4, 2026 · NWS GJT · 1 event in 1 county or zone

A low pressure system passed through the Intermountain West overnight on March 2, bringing with it showers of rain to northwestern Colorado. Moisture pooled within valleys and lingered into the morning of March 4, at which point a transient ridge moved overhead, clearing skies and calming winds.

Where it happened

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS GJT wrote it up.

A low pressure system passed through the Intermountain West overnight on March 2, bringing with it showers of rain to northwestern Colorado. Moisture pooled within valleys and lingered into the morning of March 4, at which point a transient ridge moved overhead, clearing skies and calming winds. This prompted dense fog to develop within the Yampa River Basin which persisted beyond sunrise.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Grand Junction, CO wrote its last area forecast discussion before the first event at Mar 3, 10:59 PM MST, 5 hours 1 minute earlier.

Area forecast discussion, Mar 3, 10:59 PM MST, 5 hours 1 minute before
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Hazardous weather outlook, Mar 4, 1:49 AM MST, 2 hours 11 minutes before
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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 dense fog. Local standard time, as filed.

Dense Fog, Central Yampa River Basin

When
March 4, 4:00 AM MST to 8:30 AM MST
Where
Central Yampa River Basin forecast zone
Reported by
ASOS
Coordinates
40.361, -107.805 (the zone’s center; the record gives no point)

Widespread dense fog developed within the Yampa River Basin during the morning of March 4. The KCAG ASOS at the Craig-Moffat County Airport reported several hours of reduced visibility below 1/4 mile resulting from freezing fog which lasted until a couple hours beyond sunrise. No reports of injuries, damages, or fatalities were received.

What these are

Dense Fog
Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Colorado in 2026Every state in 2026This day in weather historyWarnings in Colorado, March 2026

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 1321998.