Ontonagon County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Ontonagon County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

Every earthquake of magnitude 4 or more within 50 miles

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

More event types since 1996

Costliest events since 1996

1. Apr 13, 2023Flood$8.0 million
   National Weather Service narrative

   Michigan DOT closed Highway M-28 at Ewen due to snowmelt flooding over the bridge along the South Branch of the Ontonagon River from the 13th until the 18th. Traffic was detoured via US-2 and US-45. Ontonagon County was added to the state emergency declaration by Governor Whitmer on the 21st to assist in flood recovery efforts.

2. Jul 23, 2025Flash Flood$1.6 million
   National Weather Service narrative

   Several roads were washed out in the Misery Bay area, including Misery Bay Road, Lots Road, Kemppa Road, and Wolf Creek Road. Some residents were stranded for hours due to the washouts. Newer culverts were blown out due to the flooding.

3. Apr 28, 2013Flood$550,000
   National Weather Service narrative

   Rapid melting of significant late season snow pack caused moderate flooding of roads in the Bergland, Bruce Crossing and Rockland areas from the 28th into the 30th. Minor flooding continued into early May. Some flooding of basements was also reported. A portion of Highway M-28 was closed from Bergland to Bruce Crossing due to flooding. Governor Rick Snyder declared a state of disaster in Ontonagon County where nearly $ 550,000 in property damage occurred due to the flooding mainly to roadway infrastructure.

4. Apr 14, 2002Flood, Ontonagon$212,000
   National Weather Service narrative

   The record setting snowfall in February and March set the stage for flooding in April. During February and March of 2002, north-central and western parts of Upper Michigan received over 100 inches of snowfall. The snow pack held over 11 inches of water. The snow quickly melted during a 6 day period, 11-17 April 2002, releasing all that water into the creeks, streams. rivers and lakes. To exacerbate the situation, over 2 inches of rainfall occurred 10-12 April over much of Upper Michigan, and record high temperatures in the 70s and 80 were recorded on the 15th and 16th. During those two days, a dramatic snow melt occurred with nearly 2 feet of snow melting away. To complicate…

5. Apr 26, 2017Ice Storm, Ontonagon$100,000
   National Weather Service narrative

   Officials at the Porcupine Mountains State Park reported that higher elevations of the park received over an inch of ice accumulation from freezing rain which was then covered by 2-4 inches of wet snow. The combination of the ice and snow toppled thousands of large trees which caused extensive damage to 35-50 miles of hiking trails within the park.||Light to moderate accumulations of ice and snow were reported at lower elevations which led to minor tree damage and slippery conditions on area roads and sidewalks.

6. Jul 21, 2016Thunderstorm Wind$100,000
   National Weather Service narrative

   The Ontonagon Emergency Manager reported dozens of trees down in and around the village of Ontonagon, including several down on homes. Power was out in the village for nearly eight hours.

7. Jun 29, 2026Thunderstorm Wind$75,000
   National Weather Service narrative

   Video and photos showed significant tree damage, including trees uprooted and fallen. Two vehicles (pickup trucks) were significantly damaged from large trees falling on them. Power was also reported lost. An estimated 75 Thousand $USD of damage occurred.

8. Jun 18, 2024Flash Flood$50,000
   National Weather Service narrative

   Nearly five inches of rain from the evening of the 18th into the early morning of the 19th caused flash flooding in the Ontonagon area as a culvert washed out and resulted in the closure of Lakeshore Drive east of Ontonagon.

9. Apr 20, 1996Flood, Ontonagon$40,000
   National Weather Service narrative

   Heavy snowmelt resulted in flooding that closed several roads and minor property damage.

10. Jul 4, 2022Flash Flood$20,000
    National Weather Service narrative

    Heavy rain estimates of 4 to 5 inches from early morning through late afternoon caused a washout of Norwich Road in Ontonagon County 13 miles south of Highway M-64.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

100°FJul 2, 1911

All-time low

−48°FFeb 3, 1912

Warmest night

78°FJul 3, 1912

Coldest day

−22°FJan 19, 1994

Wettest day

5.58 inSep 17, 1955

Snowiest day

23.4 inMar 14, 2006

Hottest year

1998mean 43.5°F

Coldest year

1972mean 34.5°F

Wettest year

195151.05 in

Driest year

191022.43 in

Snowiest season

288.6 in1995-96

Station Bergland Dam (USC00200718), 1,300 ft elevation, 15.3 miles from the population centre. Daily records from 1888 to October 27, 2026; 93.3% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00200718.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.