Michigan, 2023

Excessive Heat and Heat in Michigan, September 3 to 4, 2023

September 3 to 4, 2023 · NWS MQT · 7 events in 6 counties and zones

An anomalously hot air mass being drawn into the region on southerly winds resulted in excessive heat indices exceeding 100F across portions of Upper Michigan on the 3rd and 4th.

Where it happened

Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
7

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 MQT wrote it up.

An anomalously hot air mass being drawn into the region on southerly winds resulted in excessive heat indices exceeding 100F across portions of Upper Michigan on the 3rd and 4th.

The radar

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

Open the radar archive at this moment

Event by event

6 heat, 1 excessive heat. Local standard time, as filed.

Heat, Marquette

When
September 3, 1:00 PM EST to 3:00 PM EST
Where
Marquette forecast zone
Reported by
Mesonet
Coordinates
46.663, -87.573 (the zone’s center; the record gives no point)

Heat indices ranged between 100 and 105 degrees across much of Marquette County.

Heat, Northern Houghton

When
September 3, 1:00 PM EST to 3:00 PM EST
Where
Northern Houghton forecast zone
Reported by
Mesonet
Coordinates
46.992, -88.652 (the zone’s center; the record gives no point)

Heat indices were around 100 degrees across much of northern Houghton County.

Heat, Southern Houghton

When
September 3, 1:00 PM EST to 3:00 PM EST
Where
Southern Houghton forecast zone
Reported by
Mesonet
Coordinates
46.992, -88.652 (the zone’s center; the record gives no point)

Heat indices were around 100 degrees across much of northern Houghton County.

Heat, Baraga

When
September 3, 2:00 PM EST to 5:00 PM EST
Where
Baraga forecast zone
Reported by
Mesonet
Coordinates
46.700, -88.352 (the zone’s center; the record gives no point)

Heat indices across Baraga County ranged from 100 to 105 degrees.

Heat, Ontonagon

When
September 4, 1:00 PM EST to 3:00 PM EST
Where
Ontonagon forecast zone
Reported by
Mesonet
Coordinates
46.778, -89.305 (the zone’s center; the record gives no point)

Heat indices reached near 100 degrees across much of Ontonagon County.

Heat, Alger

When
September 4, 1:00 PM EST to 3:00 PM EST
Where
Alger forecast zone
Reported by
Mesonet
Coordinates
46.451, -86.548 (the zone’s center; the record gives no point)

Heat indices reached near 100 degrees over portions of Alger County.

Excessive Heat, Marquette

When
September 4, 1:00 PM EST to 3:00 PM EST
Where
Marquette forecast zone
Reported by
Mesonet
Coordinates
46.663, -87.573 (the zone’s center; the record gives no point)

Heat indices reached between 104 and 111 degrees across much of Marquette County on the afternoon of the 4th. The high temperature at the NWS Marquette office reached 95 degrees which was not only a record high for the date but also the highest September temperature ever, breaking the previous monthly high of 93 degrees set on September 9, 2002.

What these are

Heat
Heat below excessive heat criteria that still caused deaths, injuries or significant impacts.
Excessive Heat
Heat at or above the local excessive heat warning criteria, or heat that caused deaths.

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

The same day elsewhere

More

Every storm in Michigan in 2023Every state in 2023This day in weather historyWarnings in Michigan, September 2023

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: 1131716, 1131717, 1131718, 1131712, 1131720, 1131721, 1131722.