Keweenaw County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Keweenaw 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.

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 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 22, 2023Flood$1.0 million
   National Weather Service narrative

   Local media reported Highway M-26 was closed on the evening of the 22nd due to the collapse of a retaining wall at the Silver River Bridge in Keweenaw County. The bridge's already compromised stone retaining wall eroded due to the heavy runoff from spring snow melt forcing the closure of Highway M-26. Traffic has been rerouted along US Highway 41. While MDOT was already planning on a $2.9 million project to remove and replace the bridge this summer, the snowmelt runoff contributed to the bridge failure closing the road sooner than anticipated.

2. Nov 9, 2005High Wind, Keweenaw$150,000
   National Weather Service narrative

   100-foot U.S. Coast Guard tower blown down. Antenna for tower was also damaged. Total replacement cost for the tower and antenna was estimated at $150,000 by the U.S. Coast Guard.

3. Apr 26, 2017Ice Storm, Keweenaw$100,000
   National Weather Service narrative

   The Keweenaw County Road Commission estimated between half an inch to an inch of ice accumulation from freezing rain starting from the evening of the 26th and continuing |through the 27th. The ice damaged large trees and coated roads and power lines. Schools were closed throughout the county on the 27th.

4. Nov 27, 2019Lakeshore Flood, Keweenaw$100,000
   National Weather Service narrative

   Northerly storm force winds over 50 knots whipped up waves as high as 15 to 20 feet over Lake Superior on the 27th. The high waves caused extensive lakeshore flooding and erosion near Eagle Harbor, where portions of Highway M-26 were closed due to water over the road.

5. Apr 28, 2013Flood$72,000
   National Weather Service narrative

   Rapid melting of significant late season snow pack caused minor to moerate flooding of Highway M-26 between Eagle River and Copper Harbor and along the Gay-Lac La Belle Road from the 28th into the 30th. Minor flooding continued into early May. Some flooding of basements was also reported. Governor Rick Snyder declared a state of disaster in Keweenaw County where over $ 72,000 of property damage occurred due to the flooding mainly to roadway infrastructure.

6. May 11, 2006Flood$60,000
   National Weather Service narrative

   A strong low pressure system originating over the northern Plains tracked toward Upper Michigan on the 11th. Strong winds from the storm knocked down numerous trees and power lines in central and southern Menominee County on the 11th. Wet heavy snow on the 11th and 12th caused tree limbs to break off at numerous locations across western Upper Michigan while frequent power outages were reported in Gogebic and Ontonagon counties. The heaviest snow occurred at Ironwood where nearly 8 inches accumulated. Elsewhere, 3 to 5 inches of snow was reported over higher terrain locations of the west. Heavy rain exceeding 6 inches in some areas resulted in widespread flooding across northern…

7. Dec 25, 1999High Wind, Keweenaw$50,000
   National Weather Service narrative

   A strong cold front associated with an intense low pressure center over Hudson Bay swept across Upper Michigan Christmas Night with 35 to 45 mph winds and gusts over 60 mph. The strongest winds were reported over the Keewenaw Peninsula where 90 percent of the area lost power overnight and hundreds of trees were blown down, ranging from 5 to 6 inch diameter fir trees to 12 inch birch and maple trees. Power companies worked well into the afternoon of the 26th removing downed trees and reparing damaged power lines.

8. Jun 17, 2006Thunderstorm Wind$40,000
   National Weather Service narrative

   40 to 50 large trees were snapped off or uprooted along Gratiot Lake Road within a mile of the northwest shoreline of Gratiot Lake.

9. Nov 11, 1998High Wind, Keweenaw$25,000
   National Weather Service narrative

   On the 23rd anniversary of the 1975 storm that sank the Edmond Fitzgerald on Lake Superior, a deep low pressure system (central pressure 28.41 inches of mercury) developed over the central plains and tracked northeast across western Lake Superior. Strong winds spread over Michigan's Upper Peninsula with sustained speeds of 30 to 40 mph and gusts as high as 87 mph. A gust of 94 mph was recorded by the Ontonagon County Road Commission. Damage was reported across the region with business signs blown down and roofs damaged as well as damage to homes, vehicles, utility poles, power lines and transformers from falling trees and branches. The strong winds even blew away a city's holiday…

10. Apr 28, 2014Strong Wind, Keweenaw$25,000
    National Weather Service narrative

    East winds gusting near 40 mph at times pushed a eight-foot tall ice shove from Lake Superior onshore to the east side of the Keweenaw Peninsula where the ice damaged camps near the Gay/Rice Lake area.

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

102°FJul 7, 1988

All-time low

−30°F2 times, most recently Feb 9, 1951

Warmest night

77°F2 times, most recently Jul 13, 2026

Coldest day

−16°FFeb 2, 1996

Wettest day

5.96 inJun 17, 2018

Snowiest day

26.5 inJan 18, 1996

Hottest year

2024mean 46.2°F

Coldest year

1950mean 36.2°F

Wettest year

195144.56 in

Driest year

201116.89 in

Station Hancock Houghton County Airport (USW00014858), 1,063 ft elevation, 14.8 miles from the population centre. Daily records from 1948 to October 26, 2026; 99.2% 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 USW00014858.
• 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.