Wisconsin, 2001

Dense Fog in Wisconsin, August 23, 2001

August 23, 2001 · NWS MKX · 4 events in 4 counties and zones

Very dense fog developed overnight, reducing visibilities to between zero and 1/4 mile. Several vehicle accidents were noted, and many airplane flights were delayed.

Where it happened

Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
4

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 MKX wrote it up.

Very dense fog developed overnight, reducing visibilities to between zero and 1/4 mile. Several vehicle accidents were noted, and many airplane flights were delayed. The dense fog was the result of evaporation of rain which fell on August 22nd, weak north-northeast surface winds, and partly cloudy skies.

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 Milwaukee, WI wrote its last area forecast discussion before the first event at Aug 22, 9:59 PM CST, 3 hours 1 minute earlier.

Area forecast discussion, Aug 22, 9:59 PM CST, 3 hours 1 minute before
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1059 PM CDT WED AUG 22 2001

FORECAST UPDATED DUE TO AREAS OF DENSE FOG DEVELOPING. XPCT DNS FOG
TO BCM WDSPRD OVRNGT INTO ERLY THUR MRNG.

.MKX...DNS FOG ADV TNGT AND THUR MRNG ZNS 46..47..51..52..56>60..
                                          62..72

MK

The radar

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

Open the radar archive at this moment

Event by event

4 dense fog. Local standard time, as filed.

Dense Fog, Ozaukee

When
August 23, 1:00 AM CST to 8:00 AM CST
Where
Ozaukee forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
43.403, -87.891 (the zone’s center; the record gives no point)

Dense Fog, Milwaukee

When
August 23, 1:00 AM CST to 8:00 AM CST
Where
Milwaukee forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
43.022, -87.929 (the zone’s center; the record gives no point)

Dense Fog, Racine

When
August 23, 1:00 AM CST to 8:00 AM CST
Where
Racine forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
42.730, -87.812 (the zone’s center; the record gives no point)

Dense Fog, Kenosha

When
August 23, 1:00 AM CST to 8:00 AM CST
Where
Kenosha forecast zone
Reported by
AWOS,ASOS,MESONET,ETC
Coordinates
42.573, -87.840 (the zone’s center; the record gives no point)

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 Wisconsin in 2001Every state in 2001This day in weather historyWarnings in Wisconsin, August 2001

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 2026-09-24. Each event’s entry at NCEI: 5266864, 5266865, 5266952, 5266953.